diff --git a/compiler/cpp/src/thrift/generate/t_as3_generator.cc b/compiler/cpp/src/thrift/generate/t_as3_generator.cc
index dd4d166..fa2967b 100644
--- a/compiler/cpp/src/thrift/generate/t_as3_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_as3_generator.cc
@@ -286,7 +286,7 @@
   // For each type check if it is from a differnet namespace
   for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
     t_program* program = (*m_iter)->get_type()->get_program();
-    if (program != NULL && program != program_) {
+    if (program != nullptr && program != program_) {
       string package = program->get_namespace("as3");
       if (!package.empty()) {
         if (imports.find(package + "." + (*m_iter)->get_type()->get_name()) == string::npos) {
@@ -311,7 +311,7 @@
   // For each type check if it is from a differnet namespace
   for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
     t_program* program = (*f_iter)->get_returntype()->get_program();
-    if (program != NULL && program != program_) {
+    if (program != nullptr && program != program_) {
       string package = program->get_namespace("as3");
       if (!package.empty()) {
         if (imports.find(package + "." + (*f_iter)->get_returntype()->get_name()) == string::npos) {
@@ -482,13 +482,13 @@
       indent_up();
     }
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
       string val = render_const_value(out, name, field_type, v_iter->second);
@@ -753,7 +753,7 @@
   indent(out) << "public function " << tstruct->get_name() << "() {" << endl;
   indent_up();
   for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
-    if ((*m_iter)->get_value() != NULL) {
+    if ((*m_iter)->get_value() != nullptr) {
       indent(out) << "this._" << (*m_iter)->get_name() << " = "
                   << (*m_iter)->get_value()->get_integer() << ";" << endl;
     }
@@ -1432,7 +1432,7 @@
   f_service_ << endl << as3_type_imports() << as3_thrift_imports()
              << as3_thrift_gen_imports(tservice);
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     t_type* parent = tservice->get_extends();
     string parent_namespace = parent->get_program()->get_namespace("as3");
     if (!parent_namespace.empty() && parent_namespace != package_name_) {
@@ -1458,7 +1458,7 @@
   f_service_ << endl << as3_type_imports() << as3_thrift_imports()
              << as3_thrift_gen_imports(tservice);
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     t_type* parent = tservice->get_extends();
     string parent_namespace = parent->get_program()->get_namespace("as3");
     if (!parent_namespace.empty() && parent_namespace != package_name_) {
@@ -1515,7 +1515,7 @@
  */
 void t_as3_generator::generate_service_interface(t_service* tservice) {
   string extends_iface = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends_iface = " extends " + tservice->get_extends()->get_name();
   }
 
@@ -1566,7 +1566,7 @@
 void t_as3_generator::generate_service_client(t_service* tservice) {
   string extends = "";
   string extends_client = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = tservice->get_extends()->get_name();
     extends_client = " extends " + extends + "Impl";
   }
@@ -1729,7 +1729,7 @@
   // Extends stuff
   string extends = "";
   string extends_processor = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     extends_processor = " extends " + extends + "Processor";
   }
@@ -1765,7 +1765,7 @@
 
   // Generate the server implementation
   string override = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     override = "override ";
   }
   indent(f_service_) << override
@@ -2335,7 +2335,7 @@
 
   // Check for namespacing
   t_program* program = ttype->get_program();
-  if (program != NULL && program != program_) {
+  if (program != nullptr && program != program_) {
     string package = program->get_namespace("as3");
     if (!package.empty()) {
       return package + "." + ttype->get_name();
@@ -2389,7 +2389,7 @@
   string result = "var " + tfield->get_name() + ":" + type_name(tfield->get_type());
   if (init) {
     t_type* ttype = get_true_type(tfield->get_type());
-    if (ttype->is_base_type() && tfield->get_value() != NULL) {
+    if (ttype->is_base_type() && tfield->get_value() != nullptr) {
       std::ofstream dummy;
       result += " = " + render_const_value(dummy, tfield->get_name(), ttype, tfield->get_value());
     } else if (ttype->is_base_type()) {
@@ -2580,7 +2580,7 @@
 std::string t_as3_generator::get_enum_class_name(t_type* type) {
   string package = "";
   t_program* program = type->get_program();
-  if (program != NULL && program != program_) {
+  if (program != nullptr && program != program_) {
     package = program->get_namespace("as3") + ".";
   }
   return package + type->get_name();
diff --git a/compiler/cpp/src/thrift/generate/t_c_glib_generator.cc b/compiler/cpp/src/thrift/generate/t_c_glib_generator.cc
index f1531cc..098cdb4 100644
--- a/compiler/cpp/src/thrift/generate/t_c_glib_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_c_glib_generator.cc
@@ -471,7 +471,7 @@
 
   // if we are inheriting from another service, include its header
   t_service* extends_service = tservice->get_extends();
-  if (extends_service != NULL) {
+  if (extends_service != nullptr) {
     f_header_ << "#include \"" << this->nspace_lc
               << to_lower_case(initial_caps_to_underscores(extends_service->get_name())) << ".h\""
               << endl;
@@ -1012,7 +1012,7 @@
 
     // initialize any constants that may be referenced by this initializer
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       string field_name = "";
 
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
@@ -1022,7 +1022,7 @@
           break;
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field "
           + v_iter->first->get_string();
       }
@@ -1054,7 +1054,7 @@
     scope_down(f_types_impl_);
 
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       string field_name = "";
 
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
@@ -1064,7 +1064,7 @@
           break;
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field "
           + v_iter->first->get_string();
       }
@@ -1171,7 +1171,7 @@
                   << indent() << "if (constant == NULL)" << endl;
     scope_up(f_types_impl_);
     f_types_impl_ << initializers.str() << endl
-                  << indent() << "constant = " << generate_new_hash_from_type(etype, NULL) << endl
+                  << indent() << "constant = " << generate_new_hash_from_type(etype, nullptr) << endl
                   << appenders.str();
     scope_down(f_types_impl_);
     f_types_impl_ << indent() << "return constant;" << endl;
@@ -1273,7 +1273,7 @@
   string parent_class_name = "GObject";
   string parent_type_name = "G_TYPE_OBJECT";
 
-  // The service this service extends, or NULL if it extends no
+  // The service this service extends, or nullptr if it extends no
   // service
   t_service* extends_service = tservice->get_extends();
   if (extends_service) {
@@ -1851,7 +1851,7 @@
 
   string args_indent;
 
-  // The service this service extends, or NULL if it extends no service
+  // The service this service extends, or nullptr if it extends no service
   t_service* extends_service = tservice->get_extends();
 
   // Determine the name of our parent service (if any) and the handler class'
@@ -2081,7 +2081,7 @@
   string function_name;
   string args_indent;
 
-  // The service this service extends, or NULL if it extends no service
+  // The service this service extends, or nullptr if it extends no service
   t_service* extends_service = tservice->get_extends();
 
   // Determine the name of our parent service (if any) and the
@@ -3096,7 +3096,7 @@
     t_field* member = *m_iter;
     t_const_value* member_value = member->get_value();
 
-    if (member_value != NULL) {
+    if (member_value != nullptr) {
       string member_name = member->get_name();
       t_type* member_type = get_true_type(member->get_type());
 
@@ -3145,7 +3145,7 @@
         dval += "(" + type_name(t) + ")";
       }
       t_const_value* cv = (*m_iter)->get_value();
-      if (cv != NULL) {
+      if (cv != nullptr) {
         dval += constant_value("", t, cv);
       } else {
         dval += t->is_string() ? "NULL" : "0";
@@ -3167,7 +3167,7 @@
     } else if (t->is_container()) {
       string name = (*m_iter)->get_name();
       string init_function;
-      t_type* etype = NULL;
+      t_type* etype = nullptr;
 
       if (t->is_map()) {
         t_type* key = ((t_map*)t)->get_key_type();
@@ -3175,7 +3175,7 @@
         init_function = generate_new_hash_from_type(key, value);
       } else if (t->is_set()) {
         etype = ((t_set*)t)->get_elem_type();
-        init_function = generate_new_hash_from_type(etype, NULL);
+        init_function = generate_new_hash_from_type(etype, nullptr);
       } else if (t->is_list()) {
         etype = ((t_list*)t)->get_elem_type();
         init_function = generate_new_array_from_type(etype);
@@ -3412,7 +3412,7 @@
             break;
           }
 
-          if (member_value != NULL) {
+          if (member_value != nullptr) {
             default_value << (base_type == t_base_type::TYPE_DOUBLE ? member_value->get_double()
                                                                     : member_value->get_integer());
           } else {
@@ -3431,8 +3431,8 @@
       } else if (member_type->is_enum()) {
         t_enum_value* enum_min_value = ((t_enum*)member_type)->get_min_value();
         t_enum_value* enum_max_value = ((t_enum*)member_type)->get_max_value();
-        int min_value = (enum_min_value != NULL) ? enum_min_value->get_value() : 0;
-        int max_value = (enum_max_value != NULL) ? enum_max_value->get_value() : 0;
+        int min_value = (enum_min_value != nullptr) ? enum_min_value->get_value() : 0;
+        int max_value = (enum_max_value != nullptr) ? enum_max_value->get_value() : 0;
 
         args_indent += string(18, ' ');
         f_types_impl_ << "g_param_spec_int (\"" << member_name << "\"," << endl << args_indent
@@ -4338,7 +4338,7 @@
 }
 
 string t_c_glib_generator::generate_free_func_from_type(t_type* ttype) {
-  if (ttype == NULL)
+  if (ttype == nullptr)
     return "NULL";
 
   if (ttype->is_base_type()) {
@@ -4404,7 +4404,7 @@
 }
 
 string t_c_glib_generator::generate_hash_func_from_type(t_type* ttype) {
-  if (ttype == NULL)
+  if (ttype == nullptr)
     return "NULL";
 
   if (ttype->is_base_type()) {
@@ -4442,7 +4442,7 @@
 }
 
 string t_c_glib_generator::generate_cmp_func_from_type(t_type* ttype) {
-  if (ttype == NULL)
+  if (ttype == nullptr)
     return "NULL";
 
   if (ttype->is_base_type()) {
diff --git a/compiler/cpp/src/thrift/generate/t_cl_generator.cc b/compiler/cpp/src/thrift/generate/t_cl_generator.cc
index ad7c0ef..06b6b65 100644
--- a/compiler/cpp/src/thrift/generate/t_cl_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_cl_generator.cc
@@ -314,13 +314,13 @@
     map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
 
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
 
@@ -396,7 +396,7 @@
       out << endl << indent() << " ";
     }
     out << "(" << prefix((*m_iter)->get_name()) << " " <<
-        ( (NULL != value) ? render_const_value(type, value) : "nil" ) <<
+        ( (nullptr != value) ? render_const_value(type, value) : "nil" ) <<
         " :id " << (*m_iter)->get_key();
     if ( type->is_base_type() && "string" == typespec(type) )
       if ( ((t_base_type*)type)->is_binary() )
@@ -441,7 +441,7 @@
   vector<t_function*> functions = tservice->get_functions();
   vector<t_function*>::iterator f_iter;
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends_client = type_name(tservice->get_extends());
   }
 
@@ -540,7 +540,7 @@
   string prefix = "";
   t_program* program = ttype->get_program();
 
-  if (program != NULL && program != program_)
+  if (program != nullptr && program != program_)
     prefix = package_of(program) == package() ? "" : package_of(program) + ":";
 
   string name = ttype->get_name();
diff --git a/compiler/cpp/src/thrift/generate/t_cpp_generator.cc b/compiler/cpp/src/thrift/generate/t_cpp_generator.cc
index b657038..ceaa11f 100644
--- a/compiler/cpp/src/thrift/generate/t_cpp_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_cpp_generator.cc
@@ -606,7 +606,7 @@
                 << "_VALUES_TO_NAMES(::apache::thrift::TEnumIterator(" << constants.size() << ", _k"
                 << tenum->get_name() << "Values"
                 << ", _k" << tenum->get_name() << "Names), "
-                << "::apache::thrift::TEnumIterator(-1, NULL, NULL));" << endl << endl;
+                << "::apache::thrift::TEnumIterator(-1, nullptr, nullptr));" << endl << endl;
 
   generate_enum_ostream_operator_decl(f_types_, tenum);
   generate_enum_ostream_operator(f_types_impl_, tenum);
@@ -781,7 +781,7 @@
     map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
     bool is_nonrequired_field = false;
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       is_nonrequired_field = false;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
@@ -789,7 +789,7 @@
           is_nonrequired_field = (*f_iter)->get_req() != t_field::T_REQUIRED;
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
       string val = render_const_value(out, name, field_type, v_iter->second);
@@ -1081,7 +1081,7 @@
       if ((*m_iter)->get_req() == t_field::T_REQUIRED) {
         continue;
       }
-      string isSet = ((*m_iter)->get_value() != NULL) ? "true" : "false";
+      string isSet = ((*m_iter)->get_value() != nullptr) ? "true" : "false";
       if (first) {
         first = false;
         out << ": " << (*m_iter)->get_name() << "(" << isSet << ")";
@@ -1142,7 +1142,7 @@
         }
         dval += (t->is_string() || is_reference(*m_iter)) ? "" : "0";
         t_const_value* cv = (*m_iter)->get_value();
-        if (cv != NULL) {
+        if (cv != nullptr) {
           dval = render_const_value(out, (*m_iter)->get_name(), t, cv);
         }
         if (!init_ctor) {
@@ -1163,7 +1163,7 @@
 
       if (!t->is_base_type()) {
         t_const_value* cv = (*m_iter)->get_value();
-        if (cv != NULL) {
+        if (cv != nullptr) {
           print_const_value(out, (*m_iter)->get_name(), t, cv);
         }
       }
@@ -1264,7 +1264,7 @@
 
   if (is_user_struct && !has_custom_ostream(tstruct)) {
     out << indent() << "virtual ";
-    generate_struct_print_method_decl(out, NULL);
+    generate_struct_print_method_decl(out, nullptr);
     out << ";" << endl;
   }
 
@@ -1830,7 +1830,7 @@
             << endl;
 
   t_service* extends_service = tservice->get_extends();
-  if (extends_service != NULL) {
+  if (extends_service != nullptr) {
     f_header_ << "#include \"" << get_include_prefix(*(extends_service->get_program()))
               << extends_service->get_name() << ".h\"" << endl;
   }
@@ -1977,7 +1977,7 @@
   }
 
   string extends = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = " : virtual public " + type_name(tservice->get_extends()) + style + "If";
     if (style == "CobCl" && gen_templates_) {
       // TODO(simpkins): If gen_templates_ is enabled, we currently assume all
@@ -2042,7 +2042,7 @@
   //   type.  Implementations can use dynamic_cast to cast the pointer to the
   //   subclass type if desired.
   t_service* base_service = tservice;
-  while (base_service->get_extends() != NULL) {
+  while (base_service->get_extends() != nullptr) {
     base_service = base_service->get_extends();
   }
   string base_if_name = type_name(base_service) + style + "If";
@@ -2050,7 +2050,7 @@
   // Generate the abstract factory class
   string factory_name = service_if_name + "Factory";
   string extends;
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = " : virtual public " + type_name(tservice->get_extends()) + style + "IfFactory";
   }
 
@@ -2092,7 +2092,7 @@
  */
 void t_cpp_generator::generate_service_null(t_service* tservice, string style) {
   string extends = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = " , virtual public " + type_name(tservice->get_extends()) + style + "Null";
   }
   f_header_ << "class " << service_name_ << style << "Null : virtual public " << service_name_
@@ -2278,7 +2278,7 @@
 
   string extends = "";
   string extends_multiface = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     extends_multiface = ", public " + extends + "Multiface";
   }
@@ -2399,7 +2399,7 @@
 
   string extends = "";
   string extends_client = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     // TODO(simpkins): If gen_templates_ is enabled, we currently assume all
     // parent services were also generated with templates enabled.
     extends = type_name(tservice->get_extends());
@@ -3055,7 +3055,7 @@
     factory_class_name_ += "T";
   }
 
-  if (service_->get_extends() != NULL) {
+  if (service_->get_extends() != nullptr) {
     extends_ = type_name(service_->get_extends()) + pstyle_ + "Processor";
     if (generator_->gen_templates_) {
       // TODO(simpkins): If gen_templates_ is enabled, we currently assume all
@@ -3071,7 +3071,7 @@
   vector<t_function*>::iterator f_iter;
 
   string parent_class;
-  if (service_->get_extends() != NULL) {
+  if (service_->get_extends() != nullptr) {
     parent_class = extends_;
   } else {
     if (style_ == "Cob") {
@@ -3122,7 +3122,7 @@
               << "  ProcessFunctions(ProcessFunction g, "
               << "SpecializedProcessFunction s) :" << endl << indent() << "    generic(g)," << endl
               << indent() << "    specialized(s) {}" << endl << indent()
-              << "  ProcessFunctions() : generic(NULL), specialized(NULL) "
+              << "  ProcessFunctions() : generic(nullptr), specialized(nullptr) "
               << "{}" << endl << indent() << "};" << endl << indent()
               << "typedef std::map<std::string, ProcessFunctions> "
               << "ProcessMap;" << endl;
@@ -3183,7 +3183,7 @@
     if (generator_->gen_templates_) {
       f_header_ << "ProcessFunctions(" << endl;
       if (generator_->gen_templates_only_) {
-        indent(f_header_) << "  NULL," << endl;
+        indent(f_header_) << "  nullptr," << endl;
       } else {
         indent(f_header_) << "  &" << class_name_ << "::process_" << (*f_iter)->get_name() << ","
                           << endl;
@@ -3445,18 +3445,18 @@
       out << indent() << "(void) seqid;" << endl << indent() << "(void) oprot;" << endl;
     }
 
-    out << indent() << "void* ctx = NULL;" << endl << indent()
-        << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+    out << indent() << "void* ctx = nullptr;" << endl << indent()
+        << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
         << "  ctx = this->eventHandler_->getContext(" << service_func_name << ", callContext);"
         << endl << indent() << "}" << endl << indent()
         << "::apache::thrift::TProcessorContextFreer freer("
         << "this->eventHandler_.get(), ctx, " << service_func_name << ");" << endl << endl
-        << indent() << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+        << indent() << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
         << "  this->eventHandler_->preRead(ctx, " << service_func_name << ");" << endl << indent()
         << "}" << endl << endl << indent() << argsname << " args;" << endl << indent()
         << "args.read(iprot);" << endl << indent() << "iprot->readMessageEnd();" << endl << indent()
         << "uint32_t bytes = iprot->getTransport()->readEnd();" << endl << endl << indent()
-        << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+        << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
         << "  this->eventHandler_->postRead(ctx, " << service_func_name << ", bytes);" << endl
         << indent() << "}" << endl << endl;
 
@@ -3524,7 +3524,7 @@
     }
 
     indent_up();
-    out << indent() << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+    out << indent() << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
         << "  this->eventHandler_->handlerError(ctx, " << service_func_name << ");" << endl
         << indent() << "}" << endl;
 
@@ -3542,7 +3542,7 @@
 
     // Shortcut out here for oneway functions
     if (tfunction->is_oneway()) {
-      out << indent() << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+      out << indent() << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
           << "  this->eventHandler_->asyncComplete(ctx, " << service_func_name << ");" << endl
           << indent() << "}" << endl << endl << indent() << "return;" << endl;
       indent_down();
@@ -3551,14 +3551,14 @@
     }
 
     // Serialize the result into a struct
-    out << indent() << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+    out << indent() << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
         << "  this->eventHandler_->preWrite(ctx, " << service_func_name << ");" << endl << indent()
         << "}" << endl << endl << indent() << "oprot->writeMessageBegin(\"" << tfunction->get_name()
         << "\", ::apache::thrift::protocol::T_REPLY, seqid);" << endl << indent()
         << "result.write(oprot);" << endl << indent() << "oprot->writeMessageEnd();" << endl
         << indent() << "bytes = oprot->getTransport()->writeEnd();" << endl << indent()
         << "oprot->getTransport()->flush();" << endl << endl << indent()
-        << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+        << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
         << "  this->eventHandler_->postWrite(ctx, " << service_func_name << ", bytes);" << endl
         << indent() << "}" << endl;
 
@@ -3597,32 +3597,32 @@
     }
 
     out << indent() << tservice->get_name() + "_" + tfunction->get_name() << "_args args;" << endl
-        << indent() << "void* ctx = NULL;" << endl << indent()
-        << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
-        << "  ctx = this->eventHandler_->getContext(" << service_func_name << ", NULL);" << endl
+        << indent() << "void* ctx = nullptr;" << endl << indent()
+        << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
+        << "  ctx = this->eventHandler_->getContext(" << service_func_name << ", nullptr);" << endl
         << indent() << "}" << endl << indent() << "::apache::thrift::TProcessorContextFreer freer("
         << "this->eventHandler_.get(), ctx, " << service_func_name << ");" << endl << endl
         << indent() << "try {" << endl;
     indent_up();
-    out << indent() << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+    out << indent() << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
         << "  this->eventHandler_->preRead(ctx, " << service_func_name << ");" << endl << indent()
         << "}" << endl << indent() << "args.read(iprot);" << endl << indent()
         << "iprot->readMessageEnd();" << endl << indent()
         << "uint32_t bytes = iprot->getTransport()->readEnd();" << endl << indent()
-        << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+        << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
         << "  this->eventHandler_->postRead(ctx, " << service_func_name << ", bytes);" << endl
         << indent() << "}" << endl;
     scope_down(out);
 
     // TODO(dreiss): Handle TExceptions?  Expose to server?
     out << indent() << "catch (const std::exception&) {" << endl << indent()
-        << "  if (this->eventHandler_.get() != NULL) {" << endl << indent()
+        << "  if (this->eventHandler_.get() != nullptr) {" << endl << indent()
         << "    this->eventHandler_->handlerError(ctx, " << service_func_name << ");" << endl
         << indent() << "  }" << endl << indent() << "  return cob(false);" << endl << indent()
         << "}" << endl;
 
     if (tfunction->is_oneway()) {
-      out << indent() << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+      out << indent() << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
           << "  this->eventHandler_->asyncComplete(ctx, " << service_func_name << ");" << endl
           << indent() << "}" << endl;
     }
@@ -3715,19 +3715,19 @@
             << "*>(&_return);" << endl << indent() << "result.__isset.success = true;" << endl;
       }
       // Serialize the result into a struct
-      out << endl << indent() << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
-          << "  ctx = this->eventHandler_->getContext(" << service_func_name << ", NULL);" << endl
+      out << endl << indent() << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
+          << "  ctx = this->eventHandler_->getContext(" << service_func_name << ", nullptr);" << endl
           << indent() << "}" << endl << indent()
           << "::apache::thrift::TProcessorContextFreer freer("
           << "this->eventHandler_.get(), ctx, " << service_func_name << ");" << endl << endl
-          << indent() << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+          << indent() << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
           << "  this->eventHandler_->preWrite(ctx, " << service_func_name << ");" << endl
           << indent() << "}" << endl << endl << indent() << "oprot->writeMessageBegin(\""
           << tfunction->get_name() << "\", ::apache::thrift::protocol::T_REPLY, seqid);" << endl
           << indent() << "result.write(oprot);" << endl << indent() << "oprot->writeMessageEnd();"
           << endl << indent() << "uint32_t bytes = oprot->getTransport()->writeEnd();" << endl
           << indent() << "oprot->getTransport()->flush();" << endl << indent()
-          << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+          << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
           << "  this->eventHandler_->postWrite(ctx, " << service_func_name << ", bytes);" << endl
           << indent() << "}" << endl << indent() << "return cob(true);" << endl;
       scope_down(out);
@@ -3756,8 +3756,8 @@
       }
 
       // Get the event handler context
-      out << endl << indent() << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
-          << "  ctx = this->eventHandler_->getContext(" << service_func_name << ", NULL);" << endl
+      out << endl << indent() << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
+          << "  ctx = this->eventHandler_->getContext(" << service_func_name << ", nullptr);" << endl
           << indent() << "}" << endl << indent()
           << "::apache::thrift::TProcessorContextFreer freer("
           << "this->eventHandler_.get(), ctx, " << service_func_name << ");" << endl << endl;
@@ -3783,7 +3783,7 @@
       // Handle the case where an undeclared exception is thrown
       out << " catch (std::exception& e) {" << endl;
       indent_up();
-      out << indent() << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+      out << indent() << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
           << "  this->eventHandler_->handlerError(ctx, " << service_func_name << ");" << endl
           << indent() << "}" << endl << endl << indent()
           << "::apache::thrift::TApplicationException x(e.what());" << endl << indent()
@@ -3799,14 +3799,14 @@
       scope_down(out);
 
       // Serialize the result into a struct
-      out << indent() << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+      out << indent() << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
           << "  this->eventHandler_->preWrite(ctx, " << service_func_name << ");" << endl
           << indent() << "}" << endl << endl << indent() << "oprot->writeMessageBegin(\""
           << tfunction->get_name() << "\", ::apache::thrift::protocol::T_REPLY, seqid);" << endl
           << indent() << "result.write(oprot);" << endl << indent() << "oprot->writeMessageEnd();"
           << endl << indent() << "uint32_t bytes = oprot->getTransport()->writeEnd();" << endl
           << indent() << "oprot->getTransport()->flush();" << endl << indent()
-          << "if (this->eventHandler_.get() != NULL) {" << endl << indent()
+          << "if (this->eventHandler_.get() != nullptr) {" << endl << indent()
           << "  this->eventHandler_->postWrite(ctx, " << service_func_name << ", bytes);" << endl
           << indent() << "}" << endl << indent() << "return cob(true);" << endl;
       scope_down(out);
@@ -4389,7 +4389,7 @@
   // Check if it needs to be namespaced
   string pname;
   t_program* program = ttype->get_program();
-  if (program != NULL && program != program_) {
+  if (program != nullptr && program != program_) {
     pname = class_prefix + namespace_prefix(program->get_namespace("cpp")) + ttype->get_name();
   } else {
     pname = class_prefix + ttype->get_name();
diff --git a/compiler/cpp/src/thrift/generate/t_d_generator.cc b/compiler/cpp/src/thrift/generate/t_d_generator.cc
index 65f4b44..afae5b5 100644
--- a/compiler/cpp/src/thrift/generate/t_d_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_d_generator.cc
@@ -219,7 +219,7 @@
     f_service << "import " << suffix_if_reserved(render_package(*get_program())) << program_name_ << "_types;" << endl;
 
     t_service* extends_service = tservice->get_extends();
-    if (extends_service != NULL) {
+    if (extends_service != nullptr) {
       f_service << "import " << suffix_if_reserved(render_package(*(extends_service->get_program())))
                 << suffix_if_reserved(extends_service->get_name()) << ";" << endl;
     }
@@ -227,7 +227,7 @@
     f_service << endl;
 
     string extends = "";
-    if (tservice->get_extends() != NULL) {
+    if (tservice->get_extends() != nullptr) {
       extends = " : " + suffix_if_reserved(render_type_name(tservice->get_extends()));
     }
 
@@ -299,7 +299,7 @@
         meta << "TParamMeta(`" << suffix_if_reserved((*p_iter)->get_name()) << "`, " << (*p_iter)->get_key();
 
         t_const_value* cv = (*p_iter)->get_value();
-        if (cv != NULL) {
+        if (cv != nullptr) {
           meta << ", q{" << render_const_value((*p_iter)->get_type(), cv) << "}";
         }
         meta << ")";
@@ -475,7 +475,7 @@
         t_const_value* cv = (*m_iter)->get_value();
         t_field::e_req req = (*m_iter)->get_req();
         out << ", " << render_req(req);
-        if (cv != NULL) {
+        if (cv != nullptr) {
           out << ", q{" << render_const_value((*m_iter)->get_type(), cv) << "}";
         }
         out << ")";
@@ -568,13 +568,13 @@
         const map<t_const_value*, t_const_value*, t_const_value::value_compare>& val = value->get_map();
         map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
         for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-          t_type* field_type = NULL;
+          t_type* field_type = nullptr;
           for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
             if ((*f_iter)->get_name() == v_iter->first->get_string()) {
               field_type = (*f_iter)->get_type();
             }
           }
-          if (field_type == NULL) {
+          if (field_type == nullptr) {
             throw "Type error: " + type->get_name() + " has no field "
                 + v_iter->first->get_string();
           }
diff --git a/compiler/cpp/src/thrift/generate/t_dart_generator.cc b/compiler/cpp/src/thrift/generate/t_dart_generator.cc
index fbbb9e6..65d0f53 100644
--- a/compiler/cpp/src/thrift/generate/t_dart_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_dart_generator.cc
@@ -599,13 +599,13 @@
     out << type_name(type) << " " << name << " = new " << type_name(type) << "()";
     indent_up();
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
       string val = render_const_value(out, name, field_type, v_iter->second);
@@ -827,7 +827,7 @@
   scope_up(out);
   for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
     t_type* t = get_true_type((*m_iter)->get_type());
-    if ((*m_iter)->get_value() != NULL) {
+    if ((*m_iter)->get_value() != nullptr) {
       print_const_value(out,
                         "this." + get_member_name((*m_iter)->get_name()),
                         t,
@@ -1409,7 +1409,7 @@
  */
 void t_dart_generator::generate_service_interface(t_service* tservice) {
   string extends_iface = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends_iface = " extends " + get_ttype_class_name(tservice->get_extends());
   }
 
@@ -1454,7 +1454,7 @@
 void t_dart_generator::generate_service_client(t_service* tservice) {
   string extends = "";
   string extends_client = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = get_ttype_class_name(tservice->get_extends());
     extends_client = " extends " + extends + "Client";
   }
@@ -1587,7 +1587,7 @@
   // Extends stuff
   string extends = "";
   string extends_processor = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = get_ttype_class_name(tservice->get_extends());
     extends_processor = " extends " + extends + "Processor";
   }
@@ -2193,7 +2193,7 @@
   string result = type_name(tfield->get_type()) + " " + field_name;
   if (init) {
     t_type* ttype = get_true_type(tfield->get_type());
-    if (ttype->is_base_type() && tfield->get_value() != NULL) {
+    if (ttype->is_base_type() && tfield->get_value() != nullptr) {
       std:: ofstream dummy;
       result += " = " + render_const_value(dummy, field_name, ttype, tfield->get_value());
     } else if (ttype->is_base_type()) {
diff --git a/compiler/cpp/src/thrift/generate/t_delphi_generator.cc b/compiler/cpp/src/thrift/generate/t_delphi_generator.cc
index e5bd81a..604b50a 100644
--- a/compiler/cpp/src/thrift/generate/t_delphi_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_delphi_generator.cc
@@ -956,9 +956,9 @@
 }
 
 bool t_delphi_generator::is_fully_defined_type(t_type* ttype) {
-  if ((NULL != ttype->get_program()) && (ttype->get_program() != program_)) {
+  if ((nullptr != ttype->get_program()) && (ttype->get_program() != program_)) {
     t_scope* scope = ttype->get_program()->scope();
-    if (NULL != scope->get_type(ttype->get_name())) {
+    if (nullptr != scope->get_type(ttype->get_name())) {
       // printf("type %s found in included scope %s\n", ttype->get_name().c_str(),
       // ttype->get_program()->get_name().c_str());
       return true;
@@ -1230,13 +1230,13 @@
     const map<t_const_value*, t_const_value*, t_const_value::value_compare>& val = value->get_map();
     map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
       string val = render_const_value(vars, out, name, field_type, v_iter->second);
@@ -1466,7 +1466,7 @@
     while (t->is_typedef()) {
       t = ((t_typedef*)t)->get_type();
     }
-    if ((*m_iter)->get_value() != NULL) {
+    if ((*m_iter)->get_value() != nullptr) {
       initialize_field(vars,
                        code,
                        "F" + prop_name((*m_iter)->get_name(), is_exception),
@@ -1934,7 +1934,7 @@
   indent_up();
 
   generate_delphi_doc(s_service, tservice);
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends(), true, true);
     extends_iface = extends + "." + iface_name;
     generate_delphi_doc(s_service, tservice);
@@ -1996,7 +1996,7 @@
   string implements = async_ ? "Iface, IAsync" : "Iface";
 
   generate_delphi_doc(s_service, tservice);
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends(), true, true);
     extends_client = extends + ".TClient";
   }
@@ -2281,7 +2281,7 @@
 
   string full_cls = normalize_clsnm(service_name_, "T") + ".TProcessorImpl";
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends(), true, true);
     extends_processor = extends + ".TProcessorImpl";
     indent(s_service) << "TProcessorImpl = class(" << extends_processor << ", IProcessor)" << endl;
@@ -2298,13 +2298,13 @@
   indent_impl(s_service_impl) << "constructor " << full_cls << ".Create( iface_: Iface );" << endl;
   indent_impl(s_service_impl) << "begin" << endl;
   indent_up_impl();
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     indent_impl(s_service_impl) << "inherited Create( iface_);" << endl;
   } else {
     indent_impl(s_service_impl) << "inherited Create;" << endl;
   }
   indent_impl(s_service_impl) << "Self.iface_ := iface_;" << endl;
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     indent_impl(s_service_impl) << "ASSERT( processMap_ <> nil);  // inherited" << endl;
   } else {
     indent_impl(s_service_impl)
@@ -2330,7 +2330,7 @@
   indent(s_service) << "iface_: Iface;" << endl;
   indent_down();
 
-  if (tservice->get_extends() == NULL) {
+  if (tservice->get_extends() == nullptr) {
     indent(s_service) << "protected" << endl;
     indent_up();
     indent(s_service) << "type" << endl;
@@ -3078,7 +3078,7 @@
   if (ttype->is_typedef()) {
     t_typedef* tdef = (t_typedef*)ttype;
     if (tdef->is_forward_typedef()) { // forward types according to THRIFT-2421
-      if (tdef->get_type() != NULL) {
+      if (tdef->get_type() != nullptr) {
         return type_name(tdef->get_type(),
                          b_cls,
                          b_no_postfix,
diff --git a/compiler/cpp/src/thrift/generate/t_erl_generator.cc b/compiler/cpp/src/thrift/generate/t_erl_generator.cc
index 910a38a..c96c1b2 100644
--- a/compiler/cpp/src/thrift/generate/t_erl_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_erl_generator.cc
@@ -625,13 +625,13 @@
 
     bool first = true;
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
 
@@ -909,7 +909,7 @@
 
   hrl_header(f_service_hrl_, service_name_);
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     f_service_hrl_ << "-include(\""
                    << make_safe_for_module_name(tservice->get_extends()->get_name())
                    << "_thrift.hrl\"). % inherit " << endl;
@@ -1013,7 +1013,7 @@
   }
 
   // Inheritance - pass unknown functions to base class
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     indent(f_service_) << "function_info(Function, InfoType) ->" << endl;
     indent_up();
     indent(f_service_) << make_safe_for_module_name(tservice->get_extends()->get_name())
diff --git a/compiler/cpp/src/thrift/generate/t_generator.cc b/compiler/cpp/src/thrift/generate/t_generator.cc
index ca3f5dd..f4b7150 100644
--- a/compiler/cpp/src/thrift/generate/t_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_generator.cc
@@ -235,7 +235,7 @@
   gen_map_t::iterator iter = the_map.find(language);
 
   if (iter == the_map.end()) {
-    return NULL;
+    return nullptr;
   }
 
   return iter->second->get_generator(program, parsed_options, options);
diff --git a/compiler/cpp/src/thrift/generate/t_go_generator.cc b/compiler/cpp/src/thrift/generate/t_go_generator.cc
index 4f87151..c854004 100644
--- a/compiler/cpp/src/thrift/generate/t_go_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_go_generator.cc
@@ -1193,7 +1193,7 @@
     map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
 
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       bool is_optional = false;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
@@ -1202,7 +1202,7 @@
         }
       }
 
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
       out << endl << indent() << publicize(v_iter->first->get_string()) << ": "
@@ -1303,7 +1303,7 @@
     string publicized_name;
     t_const_value* def_value;
     get_publicized_name_and_def_value(member, &publicized_name, &def_value);
-    if (!pointer_field && def_value != NULL && !omit_initialization(member)) {
+    if (!pointer_field && def_value != nullptr && !omit_initialization(member)) {
       out << endl << indent() << publicized_name << ": "
           << render_field_initial_value(member, member->get_name(), pointer_field) << ","
           << endl;
@@ -1441,7 +1441,7 @@
     string def_var_name = tstruct_name + "_" + publicized_name + "_DEFAULT";
     if ((*m_iter)->get_req() == t_field::T_OPTIONAL || is_pointer_field(*m_iter)) {
       out << indent() << "var " << def_var_name << " " << goType;
-      if (def_value != NULL) {
+      if (def_value != nullptr) {
         out << " = " << render_const_value(fieldType, def_value, (*m_iter)->get_name());
       }
       out << endl;
@@ -1913,7 +1913,7 @@
   string serviceName(publicize(tservice->get_name()));
   string interfaceName = serviceName;
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     size_t index = extends.rfind(".");
 
@@ -1956,7 +1956,7 @@
   string extends_client_new = "";
   string serviceName(publicize(tservice->get_name()));
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     size_t index = extends.rfind(".");
 
@@ -2149,7 +2149,7 @@
 
   // collect all functions including inherited functions
   t_service* parent = tservice;
-  while (parent != NULL) {
+  while (parent != nullptr) {
     vector<t_function*> p_functions = parent->get_functions();
     functions.insert(functions.end(), p_functions.begin(), p_functions.end());
 
@@ -2639,7 +2639,7 @@
   string extends_processor_new = "";
   string serviceName(publicize(tservice->get_name()));
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     size_t index = extends.rfind(".");
 
@@ -3446,7 +3446,7 @@
   std::ostringstream result;
   result << publicize(tfield->get_name()) << "=";
 
-  if (tfield->get_value() != NULL) {
+  if (tfield->get_value() != nullptr) {
     result << "thrift_spec[" << tfield->get_key() << "][4]";
   } else {
     result << "nil";
@@ -3458,7 +3458,7 @@
 /**
  * Renders a struct field initial value.
  *
- * @param tfield The field, which must have `tfield->get_value() != NULL`
+ * @param tfield The field, which must have `tfield->get_value() != nullptr`
  */
 string t_go_generator::render_field_initial_value(t_field* tfield,
                                                   const string& name,
@@ -3560,7 +3560,7 @@
 string t_go_generator::module_name(t_type* ttype) {
   t_program* program = ttype->get_program();
 
-  if (program != NULL && program != program_) {
+  if (program != nullptr && program != program_) {
     if (program->get_namespace("go").empty() ||
         program_->get_namespace("go").empty() ||
         program->get_namespace("go") != program_->get_namespace("go")) {
diff --git a/compiler/cpp/src/thrift/generate/t_gv_generator.cc b/compiler/cpp/src/thrift/generate/t_gv_generator.cc
index 2c0acf9..724a927 100644
--- a/compiler/cpp/src/thrift/generate/t_gv_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_gv_generator.cc
@@ -314,7 +314,7 @@
     for (; arg_iter != args.end(); arg_iter++) {
       f_out_ << "|<param_" << (*arg_iter)->get_name() << ">";
       f_out_ << (*arg_iter)->get_name();
-      if ((*arg_iter)->get_value() != NULL) {
+      if ((*arg_iter)->get_value() != nullptr) {
         f_out_ << " = ";
         print_const_value((*arg_iter)->get_type(), (*arg_iter)->get_value());
       }
diff --git a/compiler/cpp/src/thrift/generate/t_haxe_generator.cc b/compiler/cpp/src/thrift/generate/t_haxe_generator.cc
index 13f2cd1..7f1bb6f 100644
--- a/compiler/cpp/src/thrift/generate/t_haxe_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_haxe_generator.cc
@@ -319,7 +319,7 @@
   // For each type check if it is from a different namespace
   for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
     t_program* program = (*m_iter)->get_type()->get_program();
-    if (program != NULL && program != program_) {
+    if (program != nullptr && program != program_) {
       string package = program->get_namespace("haxe");
       if (!package.empty()) {
         if (imports.find(package + "." + (*m_iter)->get_type()->get_name()) == string::npos) {
@@ -344,7 +344,7 @@
   // For each type check if it is from a different namespace
   for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {
     t_program* program = (*f_iter)->get_returntype()->get_program();
-    if (program != NULL && program != program_) {
+    if (program != nullptr && program != program_) {
       string package = program->get_namespace("haxe");
       if (!package.empty()) {
         if (imports.find(package + "." + (*f_iter)->get_returntype()->get_name()) == string::npos) {
@@ -514,13 +514,13 @@
       indent_up();
     }
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
       string val = render_const_value(out, name, field_type, v_iter->second);
@@ -788,7 +788,7 @@
     indent(out) << "super();" << endl;
   }
   for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
-    if ((*m_iter)->get_value() != NULL) {
+    if ((*m_iter)->get_value() != nullptr) {
       indent(out) << "this." << (*m_iter)->get_name() << " = "
                   << (*m_iter)->get_value()->get_integer() << ";" << endl;
     }
@@ -1483,7 +1483,7 @@
   f_service_ << endl << haxe_type_imports() << haxe_thrift_imports()
              << haxe_thrift_gen_imports(tservice);
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     t_type* parent = tservice->get_extends();
     string parent_namespace = parent->get_program()->get_namespace("haxe");
     if (!parent_namespace.empty() && parent_namespace != package_name_) {
@@ -1504,7 +1504,7 @@
   f_service_ << autogen_comment() << haxe_package() << ";" << endl << endl << haxe_type_imports()
              << haxe_thrift_imports() << haxe_thrift_gen_imports(tservice) << endl;
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     t_type* parent = tservice->get_extends();
     string parent_namespace = parent->get_program()->get_namespace("haxe");
     if (!parent_namespace.empty() && parent_namespace != package_name_) {
@@ -1629,7 +1629,7 @@
  */
 void t_haxe_generator::generate_service_interface(t_service* tservice) {
   string extends_iface = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends_iface = " extends " + tservice->get_extends()->get_name();
   }
 
@@ -1674,7 +1674,7 @@
 void t_haxe_generator::generate_service_client(t_service* tservice) {
   string extends = "";
   string extends_client = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = get_cap_name(tservice->get_extends()->get_name());
     extends_client = " extends " + extends + "Impl";
   }
@@ -1891,7 +1891,7 @@
   // Extends stuff
   string extends = "";
   string extends_processor = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = get_cap_name(type_name(tservice->get_extends()));
     extends_processor = " extends " + extends + "Processor";
   }
@@ -1932,7 +1932,7 @@
 
   // Generate the server implementation
   string override = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     override = "override ";
   }
   indent(f_service_) << override
@@ -2606,7 +2606,7 @@
 
   // Check for namespacing
   t_program* program = ttype->get_program();
-  if (program != NULL && program != program_) {
+  if (program != nullptr && program != program_) {
     string package = program->get_namespace("haxe");
     if (!package.empty()) {
       return package + "." + ttype->get_name();
@@ -2660,7 +2660,7 @@
   string result = "var " + tfield->get_name() + " : " + type_name(tfield->get_type());
   if (init) {
     t_type* ttype = get_true_type(tfield->get_type());
-    if (ttype->is_base_type() && tfield->get_value() != NULL) {
+    if (ttype->is_base_type() && tfield->get_value() != nullptr) {
       std::ofstream dummy;
       result += " = " + render_const_value(dummy, tfield->get_name(), ttype, tfield->get_value());
     } else if (ttype->is_base_type()) {
@@ -2966,7 +2966,7 @@
 std::string t_haxe_generator::get_enum_class_name(t_type* type) {
   string package = "";
   t_program* program = type->get_program();
-  if (program != NULL /*&& program != program_*/) {
+  if (program != nullptr /*&& program != program_*/) {
     package = program->get_namespace("haxe") + ".";
   }
   return package + type->get_name();
diff --git a/compiler/cpp/src/thrift/generate/t_hs_generator.cc b/compiler/cpp/src/thrift/generate/t_hs_generator.cc
index 00c01a1..d314b8f 100644
--- a/compiler/cpp/src/thrift/generate/t_hs_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_hs_generator.cc
@@ -367,7 +367,7 @@
  * validate_types method in main.cc
  */
 string t_hs_generator::render_const_value(t_type* type, t_const_value* value) {
-  if (value == NULL)
+  if (value == nullptr)
     return type_to_default(type);
 
   type = get_true_type(type);
@@ -411,7 +411,7 @@
       int val = constant->get_value();
       if (val == value->get_integer()) {
         t_program* prog = type->get_program();
-        if (prog != NULL && prog != program_)
+        if (prog != nullptr && prog != program_)
           out << capitalize(prog->get_name()) << "_Types.";
         out << capitalize(constant->get_name());
         break;
@@ -427,13 +427,13 @@
 
     bool first = true;
     for (auto v_iter : val) {
-      t_field* field = NULL;
+      t_field* field = nullptr;
 
       for (auto f_iter : fields)
         if (f_iter->get_name() == v_iter.first->get_string())
           field = f_iter;
 
-      if (field == NULL)
+      if (field == nullptr)
         throw "type error: " + cname + " has no field " + v_iter.first->get_string();
 
       string fname = v_iter.first->get_string();
@@ -676,7 +676,7 @@
       out << "P.error \"Missing required field: " << fname << "\"";
     } else {
       if ((field->get_req() == t_field::T_OPTIONAL
-           || ((t_type*)field->get_type())->is_xception()) && field->get_value() == NULL) {
+           || ((t_type*)field->get_type())->is_xception()) && field->get_value() == nullptr) {
         out << "P.Nothing";
       } else {
         out << field_name(sname, fname) << " default_" << sname;
@@ -941,7 +941,7 @@
     indent(out) << field_name(name, mname) << " = ";
     if (field->get_req() == t_field::T_OPTIONAL
         || ((t_type*)field->get_type())->is_xception()) {
-      if (value == NULL) {
+      if (value == nullptr) {
         out << "P.Nothing";
       } else {
         out << "P.Just " << render_const_value(type, value);
@@ -973,7 +973,7 @@
   f_iface_ << endl;
 
   string sname = capitalize(service_name_);
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     string extends = type_name(tservice->get_extends());
 
     indent(f_iface_) << "import " << extends << "_Iface" << endl;
@@ -1026,7 +1026,7 @@
   string sname = capitalize(service_name_);
   indent(f_client_) << "module " << sname << "_Client(" << exports << ") where" << endl;
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     indent(f_client_) << "import " << extends << "_Client" << endl;
   }
@@ -1156,7 +1156,7 @@
   }
 
   indent(f_service_) << "_ -> ";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     f_service_ << type_name(tservice->get_extends())
                << ".proc_ handler (iprot,oprot) (name,typ,seqid)" << endl;
 
@@ -1510,7 +1510,7 @@
   string prefix = "";
   t_program* program = ttype->get_program();
 
-  if (program != NULL && program != program_)
+  if (program != nullptr && program != program_)
     if (!ttype->is_service())
       prefix = capitalize(program->get_name()) + "_Types.";
 
diff --git a/compiler/cpp/src/thrift/generate/t_html_generator.cc b/compiler/cpp/src/thrift/generate/t_html_generator.cc
index b61a712..3bff2c9 100644
--- a/compiler/cpp/src/thrift/generate/t_html_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_html_generator.cc
@@ -776,13 +776,13 @@
     const map<t_const_value*, t_const_value*, t_const_value::value_compare>& val = tvalue->get_map();
     map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + truetype->get_name() + " has no field "
             + v_iter->first->get_string();
       }
@@ -990,7 +990,7 @@
     }
     f_out_ << "</td><td>";
     t_const_value* default_val = (*mem_iter)->get_value();
-    if (default_val != NULL) {
+    if (default_val != nullptr) {
       f_out_ << "<code>";
       print_const_value((*mem_iter)->get_type(), default_val);
       f_out_ << "</code>";
@@ -1049,7 +1049,7 @@
       first = false;
       print_type((*arg_iter)->get_type());
       f_out_ << " " << (*arg_iter)->get_name();
-      if ((*arg_iter)->get_value() != NULL) {
+      if ((*arg_iter)->get_value() != nullptr) {
         f_out_ << " = ";
         print_const_value((*arg_iter)->get_type(), (*arg_iter)->get_value());
       }
diff --git a/compiler/cpp/src/thrift/generate/t_java_generator.cc b/compiler/cpp/src/thrift/generate/t_java_generator.cc
index 24637d3..8778702 100644
--- a/compiler/cpp/src/thrift/generate/t_java_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_java_generator.cc
@@ -305,7 +305,7 @@
                                         t_type* type);
 
   enum isset_type { ISSET_NONE, ISSET_PRIMITIVE, ISSET_BITSET };
-  isset_type needs_isset(t_struct* tstruct, std::string* outPrimitiveType = NULL);
+  isset_type needs_isset(t_struct* tstruct, std::string* outPrimitiveType = nullptr);
 
   /**
    * Helper rendering functions
@@ -648,13 +648,13 @@
       indent_up();
     }
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
       string val = render_const_value(out, field_type, v_iter->second);
@@ -911,7 +911,7 @@
   bool default_value = false;
   for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
     t_type* type = get_true_type((*m_iter)->get_type());
-    if ((*m_iter)->get_value() != NULL) {
+    if ((*m_iter)->get_value() != nullptr) {
       indent(out) << "super(_Fields." << constant_name((*m_iter)->get_name()) << ", "
                   << render_const_value(out, type, (*m_iter)->get_value()) << ");" << endl;
       default_value = true;
@@ -1546,7 +1546,7 @@
   indent_up();
   for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
     t_type* t = get_true_type((*m_iter)->get_type());
-    if ((*m_iter)->get_value() != NULL) {
+    if ((*m_iter)->get_value() != nullptr) {
       print_const_value(out,
                         "this." + (*m_iter)->get_name(),
                         t,
@@ -2882,7 +2882,7 @@
 void t_java_generator::generate_service_interface(t_service* tservice) {
   string extends = "";
   string extends_iface = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     extends_iface = " extends " + extends + ".Iface";
   }
@@ -2903,7 +2903,7 @@
 void t_java_generator::generate_service_async_interface(t_service* tservice) {
   string extends = "";
   string extends_iface = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     extends_iface = " extends " + extends + " .AsyncIface";
   }
@@ -2943,7 +2943,7 @@
 void t_java_generator::generate_service_client(t_service* tservice) {
   string extends = "";
   string extends_client = "";
-  if (tservice->get_extends() == NULL) {
+  if (tservice->get_extends() == nullptr) {
     extends_client = "org.apache.thrift.TServiceClient";
   } else {
     extends = type_name(tservice->get_extends());
@@ -3106,7 +3106,7 @@
 void t_java_generator::generate_service_async_client(t_service* tservice) {
   string extends = "org.apache.thrift.async.TAsyncClient";
   string extends_client = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends()) + ".AsyncClient";
   }
 
@@ -3282,7 +3282,7 @@
   // Extends stuff
   string extends = "";
   string extends_processor = "";
-  if (tservice->get_extends() == NULL) {
+  if (tservice->get_extends() == nullptr) {
     extends_processor = "org.apache.thrift.TBaseProcessor<I>";
   } else {
     extends = type_name(tservice->get_extends());
@@ -3345,7 +3345,7 @@
   // Extends stuff
   string extends = "";
   string extends_processor = "";
-  if (tservice->get_extends() == NULL) {
+  if (tservice->get_extends() == nullptr) {
     extends_processor = "org.apache.thrift.TBaseAsyncProcessor<I>";
   } else {
     extends = type_name(tservice->get_extends());
@@ -4299,7 +4299,7 @@
 
   // Check for namespacing
   t_program* program = ttype->get_program();
-  if ((program != NULL) && ((program != program_) || force_namespace)) {
+  if ((program != nullptr) && ((program != program_) || force_namespace)) {
     string package = program->get_namespace("java");
     if (!package.empty()) {
       return package + "." + ttype->get_name();
@@ -4359,7 +4359,7 @@
   }
   result += type_name(tfield->get_type()) + " " + tfield->get_name();
   if (init) {
-    if (ttype->is_base_type() && tfield->get_value() != NULL) {
+    if (ttype->is_base_type() && tfield->get_value() != nullptr) {
       std::ofstream dummy;
       result += " = " + render_const_value(dummy, ttype, tfield->get_value());
     } else if (ttype->is_base_type()) {
@@ -4998,7 +4998,7 @@
   if (count == 0) {
     return ISSET_NONE;
   } else if (count <= 64) {
-    if (outPrimitiveType != NULL) {
+    if (outPrimitiveType != nullptr) {
       if (count <= 8)
         *outPrimitiveType = "byte";
       else if (count <= 16)
@@ -5028,7 +5028,7 @@
     t_field* field = *m_iter;
     t_type* t = get_true_type(field->get_type());
 
-    if (field->get_value() != NULL) {
+    if (field->get_value() != nullptr) {
       print_const_value(out, "this." + field->get_name(), t, field->get_value(), true, true);
       continue;
     }
@@ -5420,7 +5420,7 @@
 }
 
 void t_java_generator::generate_javax_generated_annotation(ostream& out) {
-  time_t seconds = time(NULL);
+  time_t seconds = time(nullptr);
   struct tm* now = localtime(&seconds);
   indent(out) << "@javax.annotation.Generated(value = \"" << autogen_summary() << "\"";
   if (undated_generated_annotations_) {
diff --git a/compiler/cpp/src/thrift/generate/t_javame_generator.cc b/compiler/cpp/src/thrift/generate/t_javame_generator.cc
index e1694ab..b37a43b 100644
--- a/compiler/cpp/src/thrift/generate/t_javame_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_javame_generator.cc
@@ -462,13 +462,13 @@
       indent_up();
     }
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
       string val = render_const_value(out, name, field_type, v_iter->second);
@@ -1060,7 +1060,7 @@
   indent_up();
   for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
     t_type* t = get_true_type((*m_iter)->get_type());
-    if ((*m_iter)->get_value() != NULL) {
+    if ((*m_iter)->get_value() != nullptr) {
       print_const_value(out,
                         "this." + (*m_iter)->get_name(),
                         t,
@@ -1898,7 +1898,7 @@
   f_iface.open(f_interface_name.c_str());
 
   string extends_iface = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends_iface = " extends " + type_name(tservice->get_extends()) + "Iface";
   }
 
@@ -1923,7 +1923,7 @@
 void t_javame_generator::generate_service_interface(t_service* tservice) {
   string extends = "";
   string extends_iface = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     extends_iface = " extends " + extends + ".Iface";
   }
@@ -1964,7 +1964,7 @@
 void t_javame_generator::generate_service_client(t_service* tservice) {
   string extends = "";
   string extends_client = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     extends_client = " extends " + extends + ".Client";
   }
@@ -2144,7 +2144,7 @@
   // Extends stuff
   string extends = "";
   string extends_processor = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     extends_processor = " extends " + extends + ".Processor";
   }
@@ -2791,7 +2791,7 @@
 
   // Check for namespacing
   t_program* program = ttype->get_program();
-  if (program != NULL && program != program_) {
+  if (program != nullptr && program != program_) {
     string package = program->get_namespace("java");
     if (!package.empty()) {
       return package + "." + ttype->get_name();
@@ -2846,7 +2846,7 @@
   string result = type_name(tfield->get_type()) + " " + tfield->get_name();
   if (init) {
     t_type* ttype = get_true_type(tfield->get_type());
-    if (ttype->is_base_type() && tfield->get_value() != NULL) {
+    if (ttype->is_base_type() && tfield->get_value() != nullptr) {
       std::ofstream dummy;
       result += " = " + render_const_value(dummy, tfield->get_name(), ttype, tfield->get_value());
     } else if (ttype->is_base_type()) {
@@ -3208,7 +3208,7 @@
 std::string t_javame_generator::get_enum_class_name(t_type* type) {
   string package = "";
   t_program* program = type->get_program();
-  if (program != NULL && program != program_) {
+  if (program != nullptr && program != program_) {
     package = program->get_namespace("java") + ".";
   }
   return package + type->get_name();
@@ -3252,7 +3252,7 @@
   indent_up();
   for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
     t_type* t = get_true_type((*m_iter)->get_type());
-    if ((*m_iter)->get_value() != NULL) {
+    if ((*m_iter)->get_value() != nullptr) {
       print_const_value(out,
                         "this." + (*m_iter)->get_name(),
                         t,
diff --git a/compiler/cpp/src/thrift/generate/t_js_generator.cc b/compiler/cpp/src/thrift/generate/t_js_generator.cc
index 9766897..b0bed92 100644
--- a/compiler/cpp/src/thrift/generate/t_js_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_js_generator.cc
@@ -265,7 +265,7 @@
 
   std::string js_type_namespace(t_program* p) {
     if (gen_node_) {
-      if (p != NULL && p != program_) {
+      if (p != nullptr && p != program_) {
         return make_valid_nodeJs_identifier(p->get_name()) + "_ttypes.";
       }
       return "ttypes.";
@@ -325,7 +325,7 @@
    * @param t_field The field to check
    * @return string
    */
-  string ts_get_req(t_field* field) {return (field->get_req() == t_field::T_OPTIONAL || field->get_value() != NULL ? "?" : ""); }
+  string ts_get_req(t_field* field) {return (field->get_req() == t_field::T_OPTIONAL || field->get_value() != nullptr ? "?" : ""); }
 
   /**
    * Returns the documentation, if the provided documentable object has one.
@@ -738,13 +738,13 @@
     const map<t_const_value*, t_const_value*, t_const_value::value_compare>& val = value->get_map();
     map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw std::runtime_error("type error: " + type->get_name() + " has no field " + v_iter->first->get_string());
       }
       if (v_iter != val.begin())
@@ -901,7 +901,7 @@
   for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
     string dval = declare_field(*m_iter, false, true);
     t_type* t = get_true_type((*m_iter)->get_type());
-    if ((*m_iter)->get_value() != NULL && !(t->is_struct() || t->is_xception())) {
+    if ((*m_iter)->get_value() != nullptr && !(t->is_struct() || t->is_xception())) {
       dval = render_const_value((*m_iter)->get_type(), (*m_iter)->get_value());
       out << indent() << "this." << (*m_iter)->get_name() << " = " << dval << ";" << endl;
     } else {
@@ -923,7 +923,7 @@
 
     for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
       t_type* t = get_true_type((*m_iter)->get_type());
-      if ((*m_iter)->get_value() != NULL && (t->is_struct() || t->is_xception())) {
+      if ((*m_iter)->get_value() != nullptr && (t->is_struct() || t->is_xception())) {
         indent(out) << "this." << (*m_iter)->get_name() << " = "
                     << render_const_value(t, (*m_iter)->get_value()) << ";" << endl;
       }
@@ -1210,7 +1210,7 @@
   f_service_ << js_includes() << endl << render_includes() << endl;
 
   if (gen_ts_) {
-    if (tservice->get_extends() != NULL) {
+    if (tservice->get_extends() != nullptr) {
       f_service_ts_ << "/// <reference path=\"" << tservice->get_extends()->get_name()
                     << ".d.ts\" />" << endl;
     }
@@ -1262,7 +1262,7 @@
   }
 
   if (gen_node_) {
-    if (tservice->get_extends() != NULL) {
+    if (tservice->get_extends() != nullptr) {
       f_service_ << js_const_type_ <<  tservice->get_extends()->get_name() << " = require('./"
                  << tservice->get_extends()->get_name() << "');" << endl << js_const_type_
                  << tservice->get_extends()->get_name()
@@ -1311,7 +1311,7 @@
     f_service_ << prefix << service_name_ << "Processor = " << "exports.Processor";
     if (gen_ts_) {
       f_service_ts_ << endl << "declare class Processor ";
-      if (tservice->get_extends() != NULL) {
+      if (tservice->get_extends() != nullptr) {
         f_service_ts_ << "extends " << tservice->get_extends()->get_name() << "Processor ";
       }
       f_service_ts_ << "{" << endl;
@@ -1326,7 +1326,7 @@
              << "exports.Processor";
   }
 
-  bool is_subclass_service = tservice->get_extends() != NULL;
+  bool is_subclass_service = tservice->get_extends() != nullptr;
 
   // ES6 Constructor
   if (gen_es6_) {
@@ -1686,7 +1686,7 @@
  */
 void t_js_generator::generate_service_client(t_service* tservice) {
 
-  bool is_subclass_service = tservice->get_extends() != NULL;
+  bool is_subclass_service = tservice->get_extends() != nullptr;
 
   if (gen_node_) {
     string prefix = has_js_namespace(tservice->get_program()) ? js_namespace(tservice->get_program()) : js_const_type_;
@@ -1694,7 +1694,7 @@
     if (gen_ts_) {
       f_service_ts_ << ts_print_doc(tservice) << ts_indent() << ts_declare() << "class "
                     << "Client ";
-      if (tservice->get_extends() != NULL) {
+      if (tservice->get_extends() != nullptr) {
         f_service_ts_ << "extends " << tservice->get_extends()->get_name() << "Client ";
       }
       f_service_ts_ << "{" << endl;
diff --git a/compiler/cpp/src/thrift/generate/t_lua_generator.cc b/compiler/cpp/src/thrift/generate/t_lua_generator.cc
index f858562..b63569d 100644
--- a/compiler/cpp/src/thrift/generate/t_lua_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_lua_generator.cc
@@ -282,13 +282,13 @@
     const map<t_const_value*, t_const_value*, t_const_value::value_compare>& val = value->get_map();
     map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
     for (v_iter = val.begin(); v_iter != val.end();) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
 
@@ -513,7 +513,7 @@
   if (gen_requires_) {
     f_service_ << endl << "require '" << cur_ns << "ttypes'" << endl;
 
-    if (tservice->get_extends() != NULL) {
+    if (tservice->get_extends() != nullptr) {
       f_service_ << "require '" << get_namespace(tservice->get_extends()->get_program())
                  << tservice->get_extends()->get_name() << "'" << endl;
     }
@@ -550,7 +550,7 @@
 
   // Client object definition
   out << classname << " = __TObject.new(";
-  if (extends_s != NULL) {
+  if (extends_s != nullptr) {
     out << extends_s->get_name() << "Client";
   } else {
     out << "__TClient";
@@ -646,7 +646,7 @@
 
   // Define processor table
   out << endl << classname << " = __TObject.new(";
-  if (extends_s != NULL) {
+  if (extends_s != nullptr) {
     out << extends_s->get_name() << "Processor" << endl;
   } else {
     out << "__TProcessor" << endl;
diff --git a/compiler/cpp/src/thrift/generate/t_netstd_generator.cc b/compiler/cpp/src/thrift/generate/t_netstd_generator.cc
index 7be3230..0373faf 100644
--- a/compiler/cpp/src/thrift/generate/t_netstd_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_netstd_generator.cc
@@ -128,7 +128,7 @@
     return struct_name;
 }
 
-static bool field_has_default(t_field* tfield) { return tfield->get_value() != NULL; }
+static bool field_has_default(t_field* tfield) { return tfield->get_value() != nullptr; }
 
 static bool field_is_required(t_field* tfield) { return tfield->get_req() == t_field::T_REQUIRED; }
 
@@ -502,7 +502,7 @@
 
         for (v_iter = val.begin(); v_iter != val.end(); ++v_iter)
         {
-            t_field* field = NULL;
+            t_field* field = nullptr;
 
             for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter)
             {
@@ -512,7 +512,7 @@
                 }
             }
 
-            if (field == NULL)
+            if (field == nullptr)
             {
                 throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
             }
@@ -1031,7 +1031,7 @@
         t_type* t = (*m_iter)->get_type();
         t = resolve_typedef(t);
 
-        if ((*m_iter)->get_value() != NULL)
+        if ((*m_iter)->get_value() != nullptr)
         {
             if (field_is_required((*m_iter)))
             {
@@ -1924,7 +1924,7 @@
 {
     string extends = "";
     string extends_iface = "";
-    if (tservice->get_extends() != NULL)
+    if (tservice->get_extends() != nullptr)
     {
         extends = type_name(tservice->get_extends());
         extends_iface = " : " + extends + ".IAsync";
@@ -1986,7 +1986,7 @@
 {
     string extends = "";
     string extends_client = "";
-    if (tservice->get_extends() != NULL)
+    if (tservice->get_extends() != nullptr)
     {
         extends = type_name(tservice->get_extends());
         extends_client = extends + ".Client, ";
@@ -2132,7 +2132,7 @@
 
     string extends = "";
     string extends_processor = "";
-    if (tservice->get_extends() != NULL)
+    if (tservice->get_extends() != nullptr)
     {
         extends = type_name(tservice->get_extends());
         extends_processor = extends + ".AsyncProcessor, ";
@@ -3120,7 +3120,7 @@
     string the_name = check_and_correct_struct_name(normalize_name(ttype->get_name()));
 
     t_program* program = ttype->get_program();
-    if (program != NULL && program != program_)
+    if (program != nullptr && program != program_)
     {
         string ns = program->get_namespace("netstd");
         if (!ns.empty())
@@ -3434,7 +3434,7 @@
 {
     string package = "";
     t_program* program = type->get_program();
-    if (program != NULL && program != program_)
+    if (program != nullptr && program != program_)
     {
         package = program->get_namespace("netstd") + ".";
     }
diff --git a/compiler/cpp/src/thrift/generate/t_ocaml_generator.cc b/compiler/cpp/src/thrift/generate/t_ocaml_generator.cc
index a3781e8..0a96146 100644
--- a/compiler/cpp/src/thrift/generate/t_ocaml_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_ocaml_generator.cc
@@ -404,13 +404,13 @@
     const map<t_const_value*, t_const_value*, t_const_value::value_compare>& val = value->get_map();
     map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
       string fname = v_iter->first->get_string();
@@ -898,7 +898,7 @@
   f_service_ << ocaml_autogen_comment() << endl << ocaml_imports() << endl;
   f_service_i_ << ocaml_autogen_comment() << endl << ocaml_imports() << endl;
 
-  /* if (tservice->get_extends() != NULL) {
+  /* if (tservice->get_extends() != nullptr) {
     f_service_ <<
       "open " << capitalize(tservice->get_extends()->get_name()) << endl;
     f_service_i_ <<
@@ -970,7 +970,7 @@
 
   indent_up();
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     string extends = type_name(tservice->get_extends());
     indent(f_service_) << "inherit " << extends << ".iface" << endl;
     indent(f_service_i_) << "inherit " << extends << ".iface" << endl;
@@ -1004,7 +1004,7 @@
   indent(f_service_i_) << "class client : Protocol.t -> Protocol.t -> " << endl << "object" << endl;
   indent_up();
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     indent(f_service_) << "inherit " << extends << ".client iprot oprot as super" << endl;
     indent(f_service_i_) << "inherit " << extends << ".client" << endl;
@@ -1155,7 +1155,7 @@
   f_service_i_ << indent() << "inherit Processor.t" << endl << endl;
   string extends = "";
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     indent(f_service_) << "inherit " + extends + ".processor (handler :> " + extends + ".iface)"
                        << endl;
@@ -1377,7 +1377,7 @@
 void t_ocaml_generator::generate_deserialize_struct(ostream& out, t_struct* tstruct) {
   string prefix = "";
   t_program* program = tstruct->get_program();
-  if (program != NULL && program != program_) {
+  if (program != nullptr && program != program_) {
     prefix = capitalize(program->get_name()) + "_types.";
   }
   string name = decapitalize(tstruct->get_name());
@@ -1658,7 +1658,7 @@
 string t_ocaml_generator::type_name(t_type* ttype) {
   string prefix = "";
   t_program* program = ttype->get_program();
-  if (program != NULL && program != program_) {
+  if (program != nullptr && program != program_) {
     if (!ttype->is_service()) {
       prefix = capitalize(program->get_name()) + "_types.";
     }
diff --git a/compiler/cpp/src/thrift/generate/t_oop_generator.h b/compiler/cpp/src/thrift/generate/t_oop_generator.h
index f8da547..2df1be4 100644
--- a/compiler/cpp/src/thrift/generate/t_oop_generator.h
+++ b/compiler/cpp/src/thrift/generate/t_oop_generator.h
@@ -59,7 +59,7 @@
   virtual std::string get_enum_class_name(t_type* type) {
     std::string package = "";
     t_program* program = type->get_program();
-    if (program != NULL && program != program_) {
+    if (program != nullptr && program != program_) {
       package = program->get_namespace("java") + ".";
     }
     return package + type->get_name();
diff --git a/compiler/cpp/src/thrift/generate/t_perl_generator.cc b/compiler/cpp/src/thrift/generate/t_perl_generator.cc
index 80729cb..2e687dd 100644
--- a/compiler/cpp/src/thrift/generate/t_perl_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_perl_generator.cc
@@ -362,13 +362,13 @@
     const map<t_const_value*, t_const_value*, t_const_value::value_compare>& val = value->get_map();
     map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
       indent(out) << render_const_value(g_type_string, v_iter->first);
@@ -489,7 +489,7 @@
   for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
     string dval = "undef";
     t_type* t = get_true_type((*m_iter)->get_type());
-    if ((*m_iter)->get_value() != NULL && !(t->is_struct() || t->is_xception())) {
+    if ((*m_iter)->get_value() != nullptr && !(t->is_struct() || t->is_xception())) {
       dval = render_const_value((*m_iter)->get_type(), (*m_iter)->get_value());
     }
     out << indent() << "$self->{" << (*m_iter)->get_name() << "} = " << dval << ";" << endl;
@@ -500,7 +500,7 @@
 
     for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
       t_type* t = get_true_type((*m_iter)->get_type());
-      if ((*m_iter)->get_value() != NULL && (t->is_struct() || t->is_xception())) {
+      if ((*m_iter)->get_value() != nullptr && (t->is_struct() || t->is_xception())) {
         indent(out) << "$self->{" << (*m_iter)->get_name()
                     << "} = " << render_const_value(t, (*m_iter)->get_value()) << ";" << endl;
       }
@@ -680,7 +680,7 @@
   generate_use_includes(f_service_, done, tservice, true);
 
   t_service* extends_s = tservice->get_extends();
-  if (extends_s != NULL) {
+  if (extends_s != nullptr) {
     f_service_ << "use " << perl_namespace(extends_s->get_program()) << extends_s->get_name() << ";"
                << endl;
   }
@@ -712,7 +712,7 @@
   string extends = "";
   string extends_processor = "";
   t_service* extends_s = tservice->get_extends();
-  if (extends_s != NULL) {
+  if (extends_s != nullptr) {
     extends = perl_namespace(extends_s->get_program()) + extends_s->get_name();
     extends_processor = "use base qw(" + extends + "Processor);";
   }
@@ -939,7 +939,7 @@
 void t_perl_generator::generate_service_interface(t_service* tservice) {
   string extends_if = "";
   t_service* extends_s = tservice->get_extends();
-  if (extends_s != NULL) {
+  if (extends_s != nullptr) {
     extends_if = "use base qw(" + perl_namespace(extends_s->get_program()) + extends_s->get_name()
                  + "If);";
   }
@@ -964,7 +964,7 @@
   string extends = "";
   string extends_if = "";
   t_service* extends_s = tservice->get_extends();
-  if (extends_s != NULL) {
+  if (extends_s != nullptr) {
     extends = extends_s->get_name();
     extends_if = "use base qw(" + perl_namespace(extends_s->get_program()) + extends_s->get_name()
                  + "Rest);";
@@ -1024,7 +1024,7 @@
   string extends = "";
   string extends_client = "";
   t_service* extends_s = tservice->get_extends();
-  if (extends_s != NULL) {
+  if (extends_s != nullptr) {
     extends = perl_namespace(extends_s->get_program()) + extends_s->get_name();
     extends_client = "use base qw(" + extends + "Client);";
   }
diff --git a/compiler/cpp/src/thrift/generate/t_php_generator.cc b/compiler/cpp/src/thrift/generate/t_php_generator.cc
index e29ad77..c327854 100644
--- a/compiler/cpp/src/thrift/generate/t_php_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_php_generator.cc
@@ -651,13 +651,13 @@
     const map<t_const_value*, t_const_value*, t_const_value::value_compare>& val = value->get_map();
     map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
       out << indent();
@@ -846,7 +846,7 @@
   for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
     string dval = "null";
     t_type* t = get_true_type((*m_iter)->get_type());
-    if ((*m_iter)->get_value() != NULL && !(t->is_struct() || t->is_xception())) {
+    if ((*m_iter)->get_value() != nullptr && !(t->is_struct() || t->is_xception())) {
       dval = render_const_value((*m_iter)->get_type(), (*m_iter)->get_value());
     }
     generate_php_doc(out, *m_iter);
@@ -864,7 +864,7 @@
   if (members.size() > 0) {
     for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
       t_type* t = get_true_type((*m_iter)->get_type());
-      if ((*m_iter)->get_value() != NULL && (t->is_struct() || t->is_xception())) {
+      if ((*m_iter)->get_value() != nullptr && (t->is_struct() || t->is_xception())) {
         indent(out) << "$this->" << (*m_iter)->get_name() << " = "
                     << render_const_value(t, (*m_iter)->get_value()) << ";" << endl;
       }
@@ -1293,7 +1293,7 @@
 
   string extends = "";
   string extends_processor = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = tservice->get_extends()->get_name();
     extends_processor = " extends " + php_namespace(tservice->get_extends()->get_program())
                         + extends + "Processor";
@@ -1618,7 +1618,7 @@
 
   string extends = "";
   string extends_if = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = " extends " + php_namespace(tservice->get_extends()->get_program())
               + tservice->get_extends()->get_name();
     extends_if = " extends " + php_namespace(tservice->get_extends()->get_program())
@@ -1657,7 +1657,7 @@
 
   string extends = "";
   string extends_if = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = " extends " + php_namespace(tservice->get_extends()->get_program())
               + tservice->get_extends()->get_name();
     extends_if = " extends " + php_namespace(tservice->get_extends()->get_program())
@@ -1738,7 +1738,7 @@
 
   string extends = "";
   string extends_client = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = tservice->get_extends()->get_name();
     extends_client = " extends " + php_namespace(tservice->get_extends()->get_program()) + extends
                      + "Client";
diff --git a/compiler/cpp/src/thrift/generate/t_py_generator.cc b/compiler/cpp/src/thrift/generate/t_py_generator.cc
index 4be2fcc..827c482 100644
--- a/compiler/cpp/src/thrift/generate/t_py_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_py_generator.cc
@@ -252,8 +252,8 @@
   std::string type_name(t_type* ttype);
   std::string function_signature(t_function* tfunction, bool interface = false);
   std::string argument_list(t_struct* tstruct,
-                            std::vector<std::string>* pre = NULL,
-                            std::vector<std::string>* post = NULL);
+                            std::vector<std::string>* pre = nullptr,
+                            std::vector<std::string>* post = nullptr);
   std::string type_to_enum(t_type* ttype);
   std::string type_to_spec_args(t_type* ttype);
 
@@ -590,13 +590,13 @@
     const map<t_const_value*, t_const_value*, t_const_value::value_compare>& val = value->get_map();
     map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
       indent(out) << render_const_value(g_type_string, v_iter->first) << ": "
@@ -832,7 +832,7 @@
     for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {
       // Initialize fields
       t_type* type = (*m_iter)->get_type();
-      if (!type->is_base_type() && !type->is_enum() && (*m_iter)->get_value() != NULL) {
+      if (!type->is_base_type() && !type->is_enum() && (*m_iter)->get_value() != nullptr) {
         indent(out) << "if " << (*m_iter)->get_name() << " is "
                     << "self.thrift_spec[" << (*m_iter)->get_key() << "][4]:" << endl;
         indent_up();
@@ -987,7 +987,7 @@
       t_field* tfield = *f_iter;
       std::ostringstream result;
       result << tfield->get_name() << " = ";
-      if (tfield->get_value() != NULL) {
+      if (tfield->get_value() != nullptr) {
         result << render_field_default_value(tfield);
       } else {
         result << "None";
@@ -1138,7 +1138,7 @@
 
   f_service_ << py_autogen_comment() << endl << py_imports() << endl;
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     f_service_ << "import "
                << get_real_py_module(tservice->get_extends()->get_program(), gen_twisted_, package_prefix_) << "."
                << tservice->get_extends()->get_name() << endl;
@@ -1227,7 +1227,7 @@
 void t_py_generator::generate_service_interface(t_service* tservice) {
   string extends = "";
   string extends_if = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     extends_if = "(" + extends + ".Iface)";
   } else {
@@ -1272,7 +1272,7 @@
 void t_py_generator::generate_service_client(t_service* tservice) {
   string extends = "";
   string extends_client = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     if (gen_zope_interface_) {
       extends_client = "(" + extends + ".Client)";
@@ -1609,7 +1609,7 @@
   vector<t_function*> functions = tservice->get_functions();
   // Get all function from parents
   t_service* parent = tservice->get_extends();
-  while (parent != NULL) {
+  while (parent != nullptr) {
     vector<t_function*> p_functions = parent->get_functions();
     functions.insert(functions.end(), p_functions.begin(), p_functions.end());
     parent = parent->get_extends();
@@ -1818,7 +1818,7 @@
 
   string extends = "";
   string extends_processor = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     extends_processor = extends + ".Processor, ";
   }
@@ -2609,7 +2609,7 @@
 string t_py_generator::declare_argument(t_field* tfield) {
   std::ostringstream result;
   result << tfield->get_name() << "=";
-  if (tfield->get_value() != NULL) {
+  if (tfield->get_value() != nullptr) {
     result << render_field_default_value(tfield);
   } else {
     result << "None";
@@ -2624,7 +2624,7 @@
  */
 string t_py_generator::render_field_default_value(t_field* tfield) {
   t_type* type = get_true_type(tfield->get_type());
-  if (tfield->get_value() != NULL) {
+  if (tfield->get_value() != nullptr) {
     return render_const_value(type, tfield->get_value());
   } else {
     return "None";
@@ -2700,7 +2700,7 @@
   if (ttype->is_service()) {
     return get_real_py_module(program, gen_twisted_, package_prefix_) + "." + ttype->get_name();
   }
-  if (program != NULL && program != program_) {
+  if (program != nullptr && program != program_) {
     return get_real_py_module(program, gen_twisted_, package_prefix_) + ".ttypes." + ttype->get_name();
   }
   return ttype->get_name();
diff --git a/compiler/cpp/src/thrift/generate/t_rb_generator.cc b/compiler/cpp/src/thrift/generate/t_rb_generator.cc
index 61c3481..116ccaa 100644
--- a/compiler/cpp/src/thrift/generate/t_rb_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_rb_generator.cc
@@ -460,13 +460,13 @@
     const map<t_const_value*, t_const_value*, t_const_value::value_compare>& val = value->get_map();
     map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
       out.indent();
@@ -713,7 +713,7 @@
 void t_rb_generator::generate_field_data(t_rb_ofstream& out,
                                          t_type* field_type,
                                          const std::string& field_name = "",
-                                         t_const_value* field_value = NULL,
+                                         t_const_value* field_value = nullptr,
                                          bool optional = false) {
   field_type = get_true_type(field_type);
 
@@ -724,7 +724,7 @@
     out << ", :name => '" << field_name << "'";
   }
 
-  if (field_value != NULL) {
+  if (field_value != nullptr) {
     out << ", :default => ";
     render_const_value(out, field_type, field_value);
   }
@@ -788,7 +788,7 @@
 
   f_service_ << rb_autogen_comment() << endl << render_require_thrift();
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     if (namespaced_) {
       f_service_ << "require '" << rb_namespace_to_path_prefix(
                                        tservice->get_extends()->get_program()->get_namespace("rb"))
@@ -868,7 +868,7 @@
 void t_rb_generator::generate_service_client(t_service* tservice) {
   string extends = "";
   string extends_client = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = full_type_name(tservice->get_extends());
     extends_client = " < " + extends + "::Client ";
   }
@@ -992,7 +992,7 @@
 
   string extends = "";
   string extends_processor = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = full_type_name(tservice->get_extends());
     extends_processor = " < " + extends + "::Processor ";
   }
diff --git a/compiler/cpp/src/thrift/generate/t_rs_generator.cc b/compiler/cpp/src/thrift/generate/t_rs_generator.cc
index b240d99..bdadf58 100644
--- a/compiler/cpp/src/thrift/generate/t_rs_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_rs_generator.cc
@@ -2470,7 +2470,7 @@
 
 void t_rs_generator::render_sync_handler_trait(t_service *tservice) {
   string extension = "";
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     t_service* extends = tservice->get_extends();
     extension = " : " + rust_namespace(extends) + rust_sync_handler_trait_name(extends);
   }
@@ -2751,7 +2751,7 @@
   indent_up();
 
   // if there are any user-defined exceptions for this service call handle them first
-  if (tfunc->get_xceptions() != NULL && tfunc->get_xceptions()->get_sorted_members().size() > 0) {
+  if (tfunc->get_xceptions() != nullptr && tfunc->get_xceptions()->get_sorted_members().size() > 0) {
     string user_err_var("usr_err");
     f_gen_ << indent() << "thrift::Error::User(" << user_err_var << ") => {" << endl;
     indent_up();
@@ -2780,7 +2780,7 @@
 }
 
 void t_rs_generator::render_sync_handler_failed_user_exception_branch(t_function *tfunc) {
-  if (tfunc->get_xceptions() == NULL || tfunc->get_xceptions()->get_sorted_members().empty()) {
+  if (tfunc->get_xceptions() == nullptr || tfunc->get_xceptions()->get_sorted_members().empty()) {
     throw "cannot render user exception branches if no user exceptions defined";
   }
 
@@ -2918,7 +2918,7 @@
   }
 
   // any user-defined exceptions
-  if (tfunc->get_xceptions() != NULL) {
+  if (tfunc->get_xceptions() != nullptr) {
     t_struct* txceptions = tfunc->get_xceptions();
     const vector<t_field*> members = txceptions->get_sorted_members();
     vector<t_field*>::const_iterator members_iter;
@@ -3170,7 +3170,7 @@
 }
 
 bool t_rs_generator::has_args(t_function* tfunc) {
-  return tfunc->get_arglist() != NULL && !tfunc->get_arglist()->get_sorted_members().empty();
+  return tfunc->get_arglist() != nullptr && !tfunc->get_arglist()->get_sorted_members().empty();
 }
 
 bool t_rs_generator::has_non_void_args(t_function* tfunc) {
diff --git a/compiler/cpp/src/thrift/generate/t_st_generator.cc b/compiler/cpp/src/thrift/generate/t_st_generator.cc
index bc95feb..109adc7 100644
--- a/compiler/cpp/src/thrift/generate/t_st_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_st_generator.cc
@@ -406,13 +406,13 @@
     map<t_const_value*, t_const_value*, t_const_value::value_compare>::const_iterator v_iter;
 
     for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
 
@@ -934,7 +934,7 @@
   vector<t_function*> functions = tservice->get_functions();
   vector<t_function*>::iterator f_iter;
 
-  if (tservice->get_extends() != NULL) {
+  if (tservice->get_extends() != nullptr) {
     extends = type_name(tservice->get_extends());
     extends_client = extends + "Client";
   }
@@ -1000,7 +1000,7 @@
 string t_st_generator::type_name(t_type* ttype) {
   string prefix = "";
   t_program* program = ttype->get_program();
-  if (program != NULL && program != program_) {
+  if (program != nullptr && program != program_) {
     if (!ttype->is_service()) {
       prefix = program->get_name() + "_types.";
     }
diff --git a/compiler/cpp/src/thrift/generate/t_swift_generator.cc b/compiler/cpp/src/thrift/generate/t_swift_generator.cc
index 91181f6..d8eb733 100644
--- a/compiler/cpp/src/thrift/generate/t_swift_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_swift_generator.cc
@@ -1599,7 +1599,7 @@
 
     indent(out) << "public protocol " << tservice->get_name();
     t_service* parent = tservice->get_extends();
-    if (parent != NULL) {
+    if (parent != nullptr) {
       out << " : " << parent->get_name();
     }
     block_open(out);
@@ -1684,7 +1684,7 @@
 
     // Inherit from ParentClient
     t_service* parent = tservice->get_extends();
-    out << " : " << ((parent == NULL) ? "TClient" : parent->get_name() + "Client");
+    out << " : " << ((parent == nullptr) ? "TClient" : parent->get_name() + "Client");
     out <<  " /* , " << tservice->get_name() << " */";
     block_open(out);
     out << endl;
@@ -1729,7 +1729,7 @@
     // Inherit from ParentClient
     t_service* parent = tservice->get_extends();
 
-    out << " : " << ((parent == NULL) ? "T" :  parent->get_name()) + "AsyncClient<Protocol, Factory>";
+    out << " : " << ((parent == nullptr) ? "T" :  parent->get_name()) + "AsyncClient<Protocol, Factory>";
     out <<  " /* , " << tservice->get_name() << " */";
 
     block_open(out);
@@ -2646,7 +2646,7 @@
 
     for (f_iter = fields.begin(); f_iter != fields.end();) {
       t_field* tfield = *f_iter;
-      t_const_value* value = NULL;
+      t_const_value* value = nullptr;
       for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {
         if (tfield->get_name() == v_iter->first->get_string()) {
           value = v_iter->second;
diff --git a/compiler/cpp/src/thrift/generate/t_xsd_generator.cc b/compiler/cpp/src/thrift/generate/t_xsd_generator.cc
index 379e5a4..d7fb6cf 100644
--- a/compiler/cpp/src/thrift/generate/t_xsd_generator.cc
+++ b/compiler/cpp/src/thrift/generate/t_xsd_generator.cc
@@ -82,7 +82,7 @@
   void generate_element(std::ostream& out,
                         std::string name,
                         t_type* ttype,
-                        t_struct* attrs = NULL,
+                        t_struct* attrs = nullptr,
                         bool optional = false,
                         bool nillable = false,
                         bool list_element = false);
@@ -199,7 +199,7 @@
   if (ttype->is_void() || ttype->is_list()) {
     indent(out) << "<xsd:element name=\"" << name << "\"" << soptional << snillable << ">" << endl;
     indent_up();
-    if (attrs == NULL && ttype->is_void()) {
+    if (attrs == nullptr && ttype->is_void()) {
       indent(out) << "<xsd:complexType />" << endl;
     } else {
       indent(out) << "<xsd:complexType>" << endl;
@@ -216,12 +216,12 @@
         }
         f_php_ << "$GLOBALS['" << program_->get_name() << "_xsd_elt_" << name << "'] = '" << subname
                << "';" << endl;
-        generate_element(out, subname, subtype, NULL, false, false, true);
+        generate_element(out, subname, subtype, nullptr, false, false, true);
         indent_down();
         indent(out) << "</xsd:sequence>" << endl;
         indent(out) << "<xsd:attribute name=\"list\" type=\"xsd:boolean\" />" << endl;
       }
-      if (attrs != NULL) {
+      if (attrs != nullptr) {
         const vector<t_field*>& members = attrs->get_members();
         vector<t_field*>::const_iterator a_iter;
         for (a_iter = members.begin(); a_iter != members.end(); ++a_iter) {
@@ -235,7 +235,7 @@
     indent_down();
     indent(out) << "</xsd:element>" << endl;
   } else {
-    if (attrs == NULL) {
+    if (attrs == nullptr) {
       indent(out) << "<xsd:element name=\"" << name << "\""
                   << " type=\"" << type_name(ttype) << "\"" << soptional << snillable << " />"
                   << endl;
diff --git a/compiler/cpp/src/thrift/main.cc b/compiler/cpp/src/thrift/main.cc
index 4c900f7..50bdcea 100644
--- a/compiler/cpp/src/thrift/main.cc
+++ b/compiler/cpp/src/thrift/main.cc
@@ -337,7 +337,7 @@
     // Realpath!
     char rp[THRIFT_PATH_MAX];
     // cppcheck-suppress uninitvar
-    if (saferealpath(filename.c_str(), rp) == NULL) {
+    if (saferealpath(filename.c_str(), rp) == nullptr) {
       pwarning(0, "Cannot open include file %s\n", filename.c_str());
       return std::string();
     }
@@ -360,7 +360,7 @@
       // Realpath!
       char rp[THRIFT_PATH_MAX];
       // cppcheck-suppress uninitvar
-      if (saferealpath(sfilename.c_str(), rp) == NULL) {
+      if (saferealpath(sfilename.c_str(), rp) == nullptr) {
         continue;
       }
 
@@ -382,20 +382,20 @@
  * Also prints a warning if we are discarding information.
  */
 void clear_doctext() {
-  if (g_doctext != NULL) {
+  if (g_doctext != nullptr) {
     pwarning(2, "Uncaptured doctext at on line %d.", g_doctext_lineno);
   }
   free(g_doctext);
-  g_doctext = NULL;
+  g_doctext = nullptr;
 }
 
 /**
  * Reset program doctext information after processing a file
  */
 void reset_program_doctext_info() {
-  if (g_program_doctext_candidate != NULL) {
+  if (g_program_doctext_candidate != nullptr) {
     free(g_program_doctext_candidate);
-    g_program_doctext_candidate = NULL;
+    g_program_doctext_candidate = nullptr;
   }
   g_program_doctext_lineno = 0;
   g_program_doctext_status = INVALID;
@@ -406,7 +406,7 @@
  * We are sure the program doctext candidate is really the program doctext.
  */
 void declare_valid_program_doctext() {
-  if ((g_program_doctext_candidate != NULL) && (g_program_doctext_status == STILL_CANDIDATE)) {
+  if ((g_program_doctext_candidate != nullptr) && (g_program_doctext_status == STILL_CANDIDATE)) {
     g_program_doctext_status = ABSOLUTELY_SURE;
     pdebug("%s", "program doctext set to ABSOLUTELY_SURE");
   } else {
@@ -446,7 +446,7 @@
 
   // A very profound docstring.
   if (lines.empty()) {
-    return NULL;
+    return nullptr;
   }
 
   // Clear leading whitespace from the first line.
@@ -616,7 +616,7 @@
  * Emits a warning on list<byte>, binary type is typically a much better choice.
  */
 void check_for_list_of_bytes(t_type* list_elem_type) {
-  if ((g_parse_mode == PROGRAM) && (list_elem_type != NULL) && list_elem_type->is_base_type()) {
+  if ((g_parse_mode == PROGRAM) && (list_elem_type != nullptr) && list_elem_type->is_base_type()) {
     t_base_type* tbase = (t_base_type*)list_elem_type;
     if (tbase->get_base() == t_base_type::TYPE_I8) {
       pwarning(1, "Consider using the more efficient \"binary\" type instead of \"list<byte>\".");
@@ -640,12 +640,12 @@
 
 /**
  * Prints deprecation notice for old NS declarations that are no longer supported
- * If new_form is NULL, old_form is assumed to be a language identifier, such as "cpp"
- * If new_form is not NULL, both arguments are used exactly as given
+ * If new_form is nullptr, old_form is assumed to be a language identifier, such as "cpp"
+ * If new_form is not nullptr, both arguments are used exactly as given
  */
 void error_unsupported_namespace_decl(const char* old_form, const char* new_form) {
   const char* remainder = "";
-  if( new_form == NULL) {
+  if( new_form == nullptr) {
     new_form = old_form;
     remainder = "_namespace";
   }
@@ -808,13 +808,13 @@
       if (v_iter->first->get_type() != t_const_value::CV_STRING) {
         throw "type error: " + name + " struct key must be string";
       }
-      t_type* field_type = NULL;
+      t_type* field_type = nullptr;
       for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
         if ((*f_iter)->get_name() == v_iter->first->get_string()) {
           field_type = (*f_iter)->get_type();
         }
       }
-      if (field_type == NULL) {
+      if (field_type == nullptr) {
         throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();
       }
 
@@ -951,7 +951,7 @@
   g_parse_mode = PROGRAM;
   g_program = program;
   g_scope = program->scope();
-  g_parent_scope = (parent_program != NULL) ? parent_program->scope() : NULL;
+  g_parent_scope = (parent_program != nullptr) ? parent_program->scope() : nullptr;
   g_parent_prefix = program->get_name() + ".";
   g_curpath = path;
 
@@ -1004,7 +1004,7 @@
     for (iter = generator_strings.begin(); iter != generator_strings.end(); ++iter) {
       t_generator* generator = t_generator_registry::get_generator(program, *iter);
 
-      if (generator == NULL) {
+      if (generator == nullptr) {
         pwarning(1, "Unable to get a generator for \"%s\".\n", iter->c_str());
         g_generator_failure = true;
       } else if (generator) {
@@ -1032,14 +1032,14 @@
     g_incl_searchpath.push_back(old_thrift_include_path);
   }
 
-  parse(old_program, NULL);
+  parse(old_program, nullptr);
 
   g_incl_searchpath = temp_incl_searchpath;
   if (!new_thrift_include_path.empty()) {
     g_incl_searchpath.push_back(new_thrift_include_path);
   }
 
-  parse(new_program, NULL);
+  parse(new_program, nullptr);
 
   compare_namespace(new_program, old_program);
   compare_services(new_program->get_services(), old_program->get_services());
@@ -1059,7 +1059,7 @@
   bool out_path_is_absolute = false;
 
   // Setup time string
-  time_t now = time(NULL);
+  time_t now = time(nullptr);
   g_time_str = ctime(&now);
 
   // Check for necessary arguments, you gotta have at least a filename and
@@ -1081,7 +1081,7 @@
     char* arg;
 
     arg = strtok(argv[i], " ");
-    while (arg != NULL) {
+    while (arg != nullptr) {
       // Treat double dashes as single dashes
       if (arg[0] == '-' && arg[1] == '-') {
         ++arg;
@@ -1109,7 +1109,7 @@
         g_allow_64bit_consts = true;
       } else if (strcmp(arg, "-gen") == 0) {
         arg = argv[++i];
-        if (arg == NULL) {
+        if (arg == nullptr) {
           fprintf(stderr, "Missing generator specification\n");
           usage();
         }
@@ -1118,7 +1118,7 @@
         // An argument of "-I\ asdf" is invalid and has unknown results
         arg = argv[++i];
 
-        if (arg == NULL) {
+        if (arg == nullptr) {
           fprintf(stderr, "Missing Include directory\n");
           usage();
         }
@@ -1126,7 +1126,7 @@
       } else if ((strcmp(arg, "-o") == 0) || (strcmp(arg, "-out") == 0)) {
         out_path_is_absolute = (strcmp(arg, "-out") == 0) ? true : false;
         arg = argv[++i];
-        if (arg == NULL) {
+        if (arg == nullptr) {
           fprintf(stderr, "-o: missing output directory\n");
           usage();
         }
@@ -1144,14 +1144,14 @@
       } else if (strcmp(arg, "-audit") == 0) {
         g_audit = true;
         arg = argv[++i];
-        if (arg == NULL) {
+        if (arg == nullptr) {
           fprintf(stderr, "Missing old thrift file name for audit operation\n");
           usage();
         }
         char old_thrift_file_rp[THRIFT_PATH_MAX];
 
         // cppcheck-suppress uninitvar
-        if (saferealpath(arg, old_thrift_file_rp) == NULL) {
+        if (saferealpath(arg, old_thrift_file_rp) == nullptr) {
           failure("Could not open input file with realpath: %s", arg);
         }
         old_input_file = string(old_thrift_file_rp);
@@ -1159,14 +1159,14 @@
         g_audit_fatal = false;
       } else if (strcmp(arg, "-Iold") == 0) {
         arg = argv[++i];
-        if (arg == NULL) {
+        if (arg == nullptr) {
           fprintf(stderr, "Missing Include directory for old thrift file\n");
           usage();
         }
         old_thrift_include_path = string(arg);
       } else if (strcmp(arg, "-Inew") == 0) {
         arg = argv[++i];
-        if (arg == NULL) {
+        if (arg == nullptr) {
           fprintf(stderr, "Missing Include directory for new thrift file\n");
           usage();
         }
@@ -1177,7 +1177,7 @@
       }
 
       // Tokenize more
-      arg = strtok(NULL, " ");
+      arg = strtok(nullptr, " ");
     }
   }
 
@@ -1204,12 +1204,12 @@
     }
 
     char new_thrift_file_rp[THRIFT_PATH_MAX];
-    if (argv[i] == NULL) {
+    if (argv[i] == nullptr) {
       fprintf(stderr, "Missing file name of new thrift file for audit\n");
       usage();
     }
     // cppcheck-suppress uninitvar
-    if (saferealpath(argv[i], new_thrift_file_rp) == NULL) {
+    if (saferealpath(argv[i], new_thrift_file_rp) == nullptr) {
       failure("Could not open input file with realpath: %s", argv[i]);
     }
     string new_input_file(new_thrift_file_rp);
@@ -1230,12 +1230,12 @@
 
     // Real-pathify it
     char rp[THRIFT_PATH_MAX];
-    if (argv[i] == NULL) {
+    if (argv[i] == nullptr) {
       fprintf(stderr, "Missing file name\n");
       usage();
     }
     // cppcheck-suppress uninitvar
-    if (saferealpath(argv[i], rp) == NULL) {
+    if (saferealpath(argv[i], rp) == nullptr) {
       failure("Could not open input file with realpath: %s", argv[i]);
     }
     string input_file(rp);
@@ -1259,7 +1259,7 @@
     program->set_include_prefix(include_prefix);
 
     // Parse it!
-    parse(program, NULL);
+    parse(program, nullptr);
 
     // The current path is not really relevant when we are doing generation.
     // Reset the variable to make warning messages clearer.
diff --git a/compiler/cpp/src/thrift/main.h b/compiler/cpp/src/thrift/main.h
index 163b02e..4615ace 100644
--- a/compiler/cpp/src/thrift/main.h
+++ b/compiler/cpp/src/thrift/main.h
@@ -103,8 +103,8 @@
 
 /**
  * Prints deprecation notice for old NS declarations that are no longer supported
- * If new_form is NULL, old_form is assumed to be a language identifier, such as "cpp"
- * If new_form is not NULL, both arguments are used exactly as given
+ * If new_form is nullptr, old_form is assumed to be a language identifier, such as "cpp"
+ * If new_form is not nullptr, both arguments are used exactly as given
  */
 void error_unsupported_namespace_decl(const char* old_form, const char* new_form = nullptr);
 
diff --git a/compiler/cpp/src/thrift/parse/t_typedef.cc b/compiler/cpp/src/thrift/parse/t_typedef.cc
index c808685..48e861e 100644
--- a/compiler/cpp/src/thrift/parse/t_typedef.cc
+++ b/compiler/cpp/src/thrift/parse/t_typedef.cc
@@ -26,9 +26,9 @@
 }
 
 const t_type* t_typedef::get_type() const {
-  if (type_ == NULL) {
+  if (type_ == nullptr) {
     const t_type* type = get_program()->scope()->get_type(symbolic_);
-    if (type == NULL) {
+    if (type == nullptr) {
       printf("Type \"%s\" not defined\n", symbolic_.c_str());
       exit(1);
     }
diff --git a/compiler/cpp/src/thrift/thriftl.ll b/compiler/cpp/src/thrift/thriftl.ll
index 5f0ebd9..3773516 100644
--- a/compiler/cpp/src/thrift/thriftl.ll
+++ b/compiler/cpp/src/thrift/thriftl.ll
@@ -159,7 +159,7 @@
     g_doctext[strlen(g_doctext) - 1] = '\0';
     g_doctext = clean_up_doctext(g_doctext);
     g_doctext_lineno = yylineno;
-    if( (g_program_doctext_candidate == NULL) && (g_program_doctext_status == INVALID)){
+    if( (g_program_doctext_candidate == nullptr) && (g_program_doctext_status == INVALID)){
       g_program_doctext_candidate = strdup(g_doctext);
       g_program_doctext_lineno = g_doctext_lineno;
       g_program_doctext_status = STILL_CANDIDATE;
@@ -264,7 +264,7 @@
 
 {intconstant} {
   errno = 0;
-  yylval.iconst = strtoll(yytext, NULL, 10);
+  yylval.iconst = strtoll(yytext, nullptr, 10);
   if (errno == ERANGE) {
     integer_overflow(yytext);
   }
@@ -275,7 +275,7 @@
   errno = 0;
   char sign = yytext[0];
   int shift = sign == '0' ? 2 : 3;
-  yylval.iconst = strtoll(yytext+shift, NULL, 16);
+  yylval.iconst = strtoll(yytext+shift, nullptr, 16);
   if (sign == '-') {
     yylval.iconst = -yylval.iconst;
   }
diff --git a/compiler/cpp/src/thrift/thrifty.yy b/compiler/cpp/src/thrift/thrifty.yy
index df34adf..dc6838a 100644
--- a/compiler/cpp/src/thrift/thrifty.yy
+++ b/compiler/cpp/src/thrift/thrifty.yy
@@ -250,7 +250,7 @@
   HeaderList DefinitionList
     {
       pdebug("Program -> Headers DefinitionList");
-      if((g_program_doctext_candidate != NULL) && (g_program_doctext_status != ALREADY_PROCESSED))
+      if((g_program_doctext_candidate != nullptr) && (g_program_doctext_status != ALREADY_PROCESSED))
       {
         g_program->set_doc(g_program_doctext_candidate);
         g_program_doctext_status = ALREADY_PROCESSED;
@@ -262,9 +262,9 @@
     {
       if (g_parse_mode == PROGRAM) {
         $$ = g_doctext;
-        g_doctext = NULL;
+        g_doctext = nullptr;
       } else {
-        $$ = NULL;
+        $$ = nullptr;
       }
     }
 
@@ -300,7 +300,7 @@
       if (g_parse_mode == PROGRAM) {
         g_program->set_namespace($2, $3);
       }
-      if ($4 != NULL) {
+      if ($4 != nullptr) {
         g_program->set_namespace_annotations($2, $4->annotations_);
         delete $4;
       }
@@ -339,7 +339,7 @@
   DefinitionList CaptureDocText Definition
     {
       pdebug("DefinitionList -> DefinitionList Definition");
-      if ($2 != NULL && $3 != NULL) {
+      if ($2 != nullptr && $3 != nullptr) {
         $3->set_doc($2);
       }
     }
@@ -362,7 +362,7 @@
       pdebug("Definition -> TypeDefinition");
       if (g_parse_mode == PROGRAM) {
         g_scope->add_type($1->get_name(), $1);
-        if (g_parent_scope != NULL) {
+        if (g_parent_scope != nullptr) {
           g_parent_scope->add_type(g_parent_prefix + $1->get_name(), $1);
         }
         if (! g_program->is_unique_typename($1)) {
@@ -377,7 +377,7 @@
       pdebug("Definition -> Service");
       if (g_parse_mode == PROGRAM) {
         g_scope->add_service($1->get_name(), $1);
-        if (g_parent_scope != NULL) {
+        if (g_parent_scope != nullptr) {
           g_parent_scope->add_service(g_parent_prefix + $1->get_name(), $1);
         }
         g_program->add_service($1);
@@ -441,7 +441,7 @@
       validate_simple_identifier( $3);
       t_typedef *td = new t_typedef(g_program, $2, $3);
       $$ = td;
-      if ($4 != NULL) {
+      if ($4 != nullptr) {
         $$->annotations_ = $4->annotations_;
         delete $4;
       }
@@ -454,7 +454,7 @@
       $$ = $4;
       validate_simple_identifier( $2);
       $$->set_name($2);
-      if ($6 != NULL) {
+      if ($6 != nullptr) {
         $$->annotations_ = $6->annotations_;
         delete $6;
       }
@@ -468,7 +468,7 @@
           t_const_value* const_val = new t_const_value((*c_iter)->get_value());
           const_val->set_enum($$);
           g_scope->add_constant(const_name, new t_const(g_type_i32, (*c_iter)->get_name(), const_val));
-          if (g_parent_scope != NULL) {
+          if (g_parent_scope != nullptr) {
             g_parent_scope->add_constant(g_parent_prefix + const_name, new t_const(g_type_i32, (*c_iter)->get_name(), const_val));
           }
         }
@@ -494,10 +494,10 @@
     {
       pdebug("EnumDef -> EnumValue");
       $$ = $2;
-      if ($1 != NULL) {
+      if ($1 != nullptr) {
         $$->set_doc($1);
       }
-	  if ($3 != NULL) {
+	  if ($3 != nullptr) {
         $$->annotations_ = $3->annotations_;
         delete $3;
       }
@@ -536,7 +536,7 @@
       pdebug("Senum -> tok_senum tok_identifier { SenumDefList }");
       validate_simple_identifier( $2);
       $$ = new t_typedef(g_program, $4, $2);
-      if ($6 != NULL) {
+      if ($6 != nullptr) {
         $$->annotations_ = $6->annotations_;
         delete $6;
       }
@@ -574,11 +574,11 @@
         validate_const_type($$);
 
         g_scope->add_constant($3, $$);
-        if (g_parent_scope != NULL) {
+        if (g_parent_scope != nullptr) {
           g_parent_scope->add_constant(g_parent_prefix + $3, $$);
         }
       } else {
-        $$ = NULL;
+        $$ = nullptr;
       }
     }
 
@@ -681,7 +681,7 @@
       $5->set_union($1 == struct_is_union);
       $$ = $5;
       $$->set_name($2);
-      if ($7 != NULL) {
+      if ($7 != nullptr) {
         $$->annotations_ = $7->annotations_;
         delete $7;
       }
@@ -724,7 +724,7 @@
     }
 |
     {
-      $$ = NULL;
+      $$ = nullptr;
     }
 
 Xception:
@@ -735,7 +735,7 @@
       $4->set_name($2);
       $4->set_xception(true);
       $$ = $4;
-      if ($6 != NULL) {
+      if ($6 != nullptr) {
         $$->annotations_ = $6->annotations_;
         delete $6;
       }
@@ -749,7 +749,7 @@
       $$ = $6;
       $$->set_name($2);
       $$->set_extends($3);
-      if ($9 != NULL) {
+      if ($9 != nullptr) {
         $$->annotations_ = $9->annotations_;
         delete $9;
       }
@@ -769,10 +769,10 @@
   tok_extends tok_identifier
     {
       pdebug("Extends -> tok_extends tok_identifier");
-      $$ = NULL;
+      $$ = nullptr;
       if (g_parse_mode == PROGRAM) {
         $$ = g_scope->get_service($2);
-        if ($$ == NULL) {
+        if ($$ == nullptr) {
           yyerror("Service \"%s\" has not been defined.", $2);
           exit(1);
         }
@@ -780,7 +780,7 @@
     }
 |
     {
-      $$ = NULL;
+      $$ = nullptr;
     }
 
 FunctionList:
@@ -802,10 +802,10 @@
       validate_simple_identifier( $4);
       $6->set_name(std::string($4) + "_args");
       $$ = new t_function($3, $4, $6, $8, $2);
-      if ($1 != NULL) {
+      if ($1 != nullptr) {
         $$->set_doc($1);
       }
-      if ($9 != NULL) {
+      if ($9 != nullptr) {
         $$->annotations_ = $9->annotations_;
         delete $9;
       }
@@ -868,20 +868,20 @@
       $$ = new t_field($4, $6, $2.value);
       $$->set_reference($5);
       $$->set_req($3);
-      if ($7 != NULL) {
+      if ($7 != nullptr) {
         g_scope->resolve_const_value($7, $4);
         validate_field_value($$, $7);
         $$->set_value($7);
       }
       $$->set_xsd_optional($8);
       $$->set_xsd_nillable($9);
-      if ($1 != NULL) {
+      if ($1 != nullptr) {
         $$->set_doc($1);
       }
-      if ($10 != NULL) {
+      if ($10 != nullptr) {
         $$->set_xsd_attrs($10);
       }
-      if ($11 != NULL) {
+      if ($11 != nullptr) {
         $$->annotations_ = $11->annotations_;
         delete $11;
       }
@@ -974,12 +974,12 @@
       if (g_parse_mode == PROGRAM) {
         $$ = $2;
       } else {
-        $$ = NULL;
+        $$ = nullptr;
       }
     }
 |
     {
-      $$ = NULL;
+      $$ = nullptr;
     }
 
 FunctionType:
@@ -1000,11 +1000,11 @@
       pdebug("FieldType -> tok_identifier");
       if (g_parse_mode == INCLUDES) {
         // Ignore identifiers in include mode
-        $$ = NULL;
+        $$ = nullptr;
       } else {
         // Lookup the identifier in the current scope
         $$ = g_scope->get_type($1);
-        if ($$ == NULL) {
+        if ($$ == nullptr) {
           /*
            * Either this type isn't yet declared, or it's never
              declared.  Either way allow it and we'll figure it out
@@ -1028,7 +1028,7 @@
 BaseType: SimpleBaseType TypeAnnotations
     {
       pdebug("BaseType -> SimpleBaseType TypeAnnotations");
-      if ($2 != NULL) {
+      if ($2 != nullptr) {
         $$ = new t_base_type(*static_cast<t_base_type*>($1));
         $$->annotations_ = $2->annotations_;
         delete $2;
@@ -1088,7 +1088,7 @@
     {
       pdebug("ContainerType -> SimpleContainerType TypeAnnotations");
       $$ = $1;
-      if ($2 != NULL) {
+      if ($2 != nullptr) {
         $$->annotations_ = $2->annotations_;
         delete $2;
       }
@@ -1116,7 +1116,7 @@
     {
       pdebug("MapType -> tok_map <FieldType, FieldType>");
       $$ = new t_map($4, $6);
-      if ($2 != NULL) {
+      if ($2 != nullptr) {
         ((t_container*)$$)->set_cpp_name(std::string($2));
       }
     }
@@ -1126,7 +1126,7 @@
     {
       pdebug("SetType -> tok_set<FieldType>");
       $$ = new t_set($4);
-      if ($2 != NULL) {
+      if ($2 != nullptr) {
         ((t_container*)$$)->set_cpp_name(std::string($2));
       }
     }
@@ -1137,7 +1137,7 @@
       pdebug("ListType -> tok_list<FieldType>");
       check_for_list_of_bytes($3);
       $$ = new t_list($3);
-      if ($5 != NULL) {
+      if ($5 != nullptr) {
         ((t_container*)$$)->set_cpp_name(std::string($5));
       }
     }
@@ -1149,7 +1149,7 @@
     }
 |
     {
-      $$ = NULL;
+      $$ = nullptr;
     }
 
 TypeAnnotations:
@@ -1160,7 +1160,7 @@
     }
 |
     {
-      $$ = NULL;
+      $$ = nullptr;
     }
 
 TypeAnnotationList:
diff --git a/contrib/async-test/test-server.cpp b/contrib/async-test/test-server.cpp
index b304e1b..9e696c9 100644
--- a/contrib/async-test/test-server.cpp
+++ b/contrib/async-test/test-server.cpp
@@ -28,7 +28,7 @@
 
  public:
   AggrAsyncHandler()
-    : eb_(NULL)
+    : eb_(nullptr)
     , pfact_(new TBinaryProtocolFactory())
   {
     leaf_ports_.push_back(8081);
diff --git a/contrib/fb303/TClientInfo.cpp b/contrib/fb303/TClientInfo.cpp
index 1fc6612..a4b00cf 100644
--- a/contrib/fb303/TClientInfo.cpp
+++ b/contrib/fb303/TClientInfo.cpp
@@ -34,7 +34,7 @@
   eraseAddr();
   initTime();
   ncalls_ = 0;
-  if (addr != NULL) {
+  if (addr != nullptr) {
     if (addr->sa_family == AF_INET) {
       memcpy((void*)&addr_.ipv4, (const void *)addr, sizeof(sockaddr_in));
     }
@@ -55,7 +55,7 @@
   case AF_INET6:
     return inet_ntop(AF_INET6, &addr_.ipv6.sin6_addr, buf, len);
   default:
-    return NULL;
+    return nullptr;
   }
 }
 
@@ -70,7 +70,7 @@
 
 const char* TClientInfoConnection::getCall() const {
   if (call_[0] == '\0') {
-      return NULL;
+      return nullptr;
   }
   return call_;
 }
@@ -90,7 +90,7 @@
 
 TClientInfoConnection* TClientInfo::getConnection(int fd, bool grow) {
   if (fd < 0 || (!grow && fd >= info_.size())) {
-    return NULL;
+    return nullptr;
   }
   return &info_[fd];
 }
@@ -119,7 +119,7 @@
 void TClientInfoServerHandler::processContext(void* connectionContext,
                                               shared_ptr<TTransport> transport) {
   Connect* call = static_cast<Connect*>(connectionContext);
-  if (call->callInfo_ == NULL) {
+  if (call->callInfo_ == nullptr) {
     if (typeid(*(transport.get())) == typeid(TSocket)) {
       TSocket* tsocket = static_cast<TSocket*>(transport.get());
       int fd = tsocket->getSocketFD();
@@ -127,7 +127,7 @@
         return;
       }
       call->callInfo_ = call->clientInfo_->getConnection(fd, true);
-      assert(call->callInfo_ != NULL);
+      assert(call->callInfo_ != nullptr);
       socklen_t len;
         call->callInfo_->recordAddr(tsocket->getCachedAddress(&len));
     }
@@ -142,13 +142,13 @@
   for (int i = 0; i < clientInfo_.size(); ++i) {
     TClientInfoConnection* info = clientInfo_.getConnection(i, false);
     const char* callStr = info->getCall();
-    if (callStr == NULL) {
+    if (callStr == nullptr) {
       continue;
     }
 
     char addrBuf[INET6_ADDRSTRLEN];
     const char* addrStr = info->getAddr(addrBuf, sizeof addrBuf);
-    if (addrStr == NULL) {
+    if (addrStr == nullptr) {
       // cerr << "no addr!" << endl;
       continue;
     }
@@ -168,11 +168,11 @@
 void* TClientInfoCallHandler::getContext(const char* fn_name, void* serverContext) {
   if (serverContext) {
     TClientInfoConnection* callInfo =  static_cast<TClientInfoServerHandler::Connect*>(serverContext)->callInfo_;
-    if (callInfo != NULL) {
+    if (callInfo != nullptr) {
       callInfo->recordCall(fn_name);
     }
   }
-  return NULL;
+  return nullptr;
 }
 
 } } } // namespace apache::thrift::server
diff --git a/contrib/fb303/TClientInfo.h b/contrib/fb303/TClientInfo.h
index 6668c19..e3859a7 100644
--- a/contrib/fb303/TClientInfo.h
+++ b/contrib/fb303/TClientInfo.h
@@ -174,7 +174,7 @@
   void eraseAddr();
 
   /**
-   * Return a string representing the present address, or NULL if none.
+   * Return a string representing the present address, or nullptr if none.
    * Copies the string into the buffer provided.
    */
   const char* getAddr(char* buf, int len) const;
@@ -193,7 +193,7 @@
   /**
    * Return as string the thrift call either currently being processed or
    * most recently processed if the connection is still open for additional
-   * calls.  Returns NULL if a call hasn't been made yet or processing
+   * calls.  Returns nullptr if a call hasn't been made yet or processing
    * has ended.
    */
   const char* getCall() const;
@@ -229,7 +229,7 @@
    * Return the info object for a given file descriptor.  If "grow" is true
    * extend the info vector if required (such as for a file descriptor not seen
    * before).  If "grow" is false and the info vector isn't large enough,
-   * or if "fd" is negative, return NULL.
+   * or if "fd" is negative, return nullptr.
    */
   TClientInfoConnection* getConnection(int fd, bool grow);
 
@@ -258,7 +258,7 @@
 
     explicit Connect(TClientInfo* clientInfo)
       : clientInfo_(clientInfo)
-      , callInfo_(NULL) {
+      , callInfo_(nullptr) {
     }
   };
 
diff --git a/contrib/fb303/cpp/FacebookBase.cpp b/contrib/fb303/cpp/FacebookBase.cpp
index 3c56975..eb2e63c 100644
--- a/contrib/fb303/cpp/FacebookBase.cpp
+++ b/contrib/fb303/cpp/FacebookBase.cpp
@@ -24,7 +24,7 @@
 
 FacebookBase::FacebookBase(std::string name) :
   name_(name) {
-  aliveSince_ = (int64_t) time(NULL);
+  aliveSince_ = (int64_t) time(nullptr);
 }
 
 inline void FacebookBase::getName(std::string& _return) {
diff --git a/contrib/fb303/cpp/FacebookBase.h b/contrib/fb303/cpp/FacebookBase.h
index daa5246..e0be4bf 100644
--- a/contrib/fb303/cpp/FacebookBase.h
+++ b/contrib/fb303/cpp/FacebookBase.h
@@ -65,7 +65,7 @@
   virtual void reinitialize() {}
 
   virtual void shutdown() {
-    if (server_.get() != NULL) {
+    if (server_.get() != nullptr) {
       server_->stop();
     }
   }
diff --git a/contrib/fb303/cpp/ServiceTracker.cpp b/contrib/fb303/cpp/ServiceTracker.cpp
index 7a61b21..a2e670c 100644
--- a/contrib/fb303/cpp/ServiceTracker.cpp
+++ b/contrib/fb303/cpp/ServiceTracker.cpp
@@ -46,7 +46,7 @@
     checkpointServices_(0)
 {
   if (featureCheckpoint_) {
-    time_t now = time(NULL);
+    time_t now = time(nullptr);
     checkpointTime_ = now;
   } else {
     checkpointTime_ = 0;
@@ -105,7 +105,7 @@
   if (featureThreadCheck_ && !serviceMethod.featureLogOnly_) {
     // note: Might want to put these messages in reportCheckpoint() if
     // log is getting spammed.
-    if (threadManager_ != NULL) {
+    if (threadManager_ != nullptr) {
       size_t idle_count = threadManager_->idleWorkerCount();
       if (idle_count == 0) {
         stringstream message;
@@ -211,7 +211,7 @@
 
         // maybe report checkpoint
         // note: ...if it's been long enough since the last report.
-        time_t now = time(NULL);
+        time_t now = time(nullptr);
         uint64_t check_interval = now - checkpointTime_;
         if (check_interval >= CHECKPOINT_MINIMUM_INTERVAL_SECONDS) {
           reportCheckpoint();
@@ -239,7 +239,7 @@
 void
 ServiceTracker::reportCheckpoint()
 {
-  time_t now = time(NULL);
+  time_t now = time(nullptr);
 
   uint64_t check_count = checkpointServices_;
   uint64_t check_interval = now - checkpointTime_;
@@ -282,7 +282,7 @@
           << " checkpoint_speed_sum:" << check_duration
           << " lifetime_time:" << life_interval
           << " lifetime_services:" << life_count;
-  if (featureThreadCheck_ && threadManager_ != NULL) {
+  if (featureThreadCheck_ && threadManager_ != nullptr) {
     size_t worker_count = threadManager_->workerCount();
     size_t idle_count = threadManager_->idleWorkerCount();
     message << " total_workers:" << worker_count
@@ -321,7 +321,7 @@
 {
   if (level <= LOG_LEVEL) {
     string level_string;
-    time_t now = time(NULL);
+    time_t now = time(nullptr);
     char now_pretty[26];
     ctime_r(&now, now_pretty);
     now_pretty[24] = '\0';
@@ -356,20 +356,20 @@
  */
 Stopwatch::Stopwatch()
 {
-  gettimeofday(&startTime_, NULL);
+  gettimeofday(&startTime_, nullptr);
 }
 
 void
 Stopwatch::reset()
 {
-  gettimeofday(&startTime_, NULL);
+  gettimeofday(&startTime_, nullptr);
 }
 
 uint64_t
 Stopwatch::elapsedUnits(Stopwatch::Unit unit, string *label) const
 {
   timeval now_time;
-  gettimeofday(&now_time, NULL);
+  gettimeofday(&now_time, nullptr);
   time_t duration_secs = now_time.tv_sec - startTime_.tv_sec;
 
   uint64_t duration_units;
@@ -377,7 +377,7 @@
   case UNIT_SECONDS:
     duration_units = duration_secs
       + (now_time.tv_usec - startTime_.tv_usec + 500000) / 1000000;
-    if (NULL != label) {
+    if (nullptr != label) {
       stringstream ss_label;
       ss_label << duration_units << " secs";
       label->assign(ss_label.str());
@@ -386,7 +386,7 @@
   case UNIT_MICROSECONDS:
     duration_units = duration_secs * 1000000
       + now_time.tv_usec - startTime_.tv_usec;
-    if (NULL != label) {
+    if (nullptr != label) {
       stringstream ss_label;
       ss_label << duration_units << " us";
       label->assign(ss_label.str());
@@ -396,7 +396,7 @@
   default:
     duration_units = duration_secs * 1000
       + (now_time.tv_usec - startTime_.tv_usec + 500) / 1000;
-    if (NULL != label) {
+    if (nullptr != label) {
       stringstream ss_label;
       ss_label << duration_units << " ms";
       label->assign(ss_label.str());
diff --git a/contrib/fb303/cpp/ServiceTracker.h b/contrib/fb303/cpp/ServiceTracker.h
index 9a3edd8..faaa4a7 100644
--- a/contrib/fb303/cpp/ServiceTracker.h
+++ b/contrib/fb303/cpp/ServiceTracker.h
@@ -120,7 +120,7 @@
 public:
   enum Unit { UNIT_SECONDS, UNIT_MILLISECONDS, UNIT_MICROSECONDS };
   Stopwatch();
-  uint64_t elapsedUnits(Unit unit, std::string *label = NULL) const;
+  uint64_t elapsedUnits(Unit unit, std::string *label = nullptr) const;
   void reset();
 private:
   timeval startTime_;
diff --git a/contrib/transport-sample/ThriftCommon.cpp b/contrib/transport-sample/ThriftCommon.cpp
index 60ebf7a..2b676a8 100644
--- a/contrib/transport-sample/ThriftCommon.cpp
+++ b/contrib/transport-sample/ThriftCommon.cpp
@@ -23,7 +23,7 @@
 			(int)boost::shared_dynamic_cast<TPipeServer>(transport)->getClientWrtPipeHandle());
 
 		//spawn the child process
-		if (!CreateProcessA(NULL, handles, NULL,NULL,TRUE,0,NULL,NULL,&si,&pi))
+		if (!CreateProcessA(nullptr, handles, nullptr,nullptr,TRUE,0,nullptr,nullptr,&si,&pi))
 		{
 			GlobalOutput.perror("TPipeServer CreateProcess failed, GLE=", GetLastError());
 			return false;
diff --git a/contrib/zeromq/TZmqServer.cpp b/contrib/zeromq/TZmqServer.cpp
index 88660a3..1ad7db8 100644
--- a/contrib/zeromq/TZmqServer.cpp
+++ b/contrib/zeromq/TZmqServer.cpp
@@ -41,7 +41,7 @@
       outputProtocolFactory_->getProtocol(outputTransport));
   shared_ptr<TMemoryBuffer> transport(new TMemoryBuffer);
 
-  processor_->process(inputProtocol, outputProtocol, NULL);
+  processor_->process(inputProtocol, outputProtocol, nullptr);
 
   if (zmq_type_ == ZMQ_REP) {
     uint8_t* buf;
diff --git a/lib/c_glib/test/testthrifttestclient.cpp b/lib/c_glib/test/testthrifttestclient.cpp
index 20fbcdb..5732996 100644
--- a/lib/c_glib/test/testthrifttestclient.cpp
+++ b/lib/c_glib/test/testthrifttestclient.cpp
@@ -384,11 +384,11 @@
   // create a C client
   tsocket = (ThriftSocket *) g_object_new (THRIFT_TYPE_SOCKET,
                           "hostname", "localhost",
-                          "port", TEST_PORT, NULL);
+                          "port", TEST_PORT, nullptr);
   protocol = (ThriftBinaryProtocol *) g_object_new (THRIFT_TYPE_BINARY_PROTOCOL,
                            "transport",
-                           tsocket, NULL);
-  client = (TTestThriftTestClient *) g_object_new (T_TEST_TYPE_THRIFT_TEST_CLIENT, "input_protocol", protocol, "output_protocol", protocol, NULL);
+                           tsocket, nullptr);
+  client = (TTestThriftTestClient *) g_object_new (T_TEST_TYPE_THRIFT_TEST_CLIENT, "input_protocol", protocol, "output_protocol", protocol, nullptr);
   iface = T_TEST_THRIFT_TEST_IF (client);
 
   // open and send
diff --git a/lib/cpp/src/thrift/TOutput.cpp b/lib/cpp/src/thrift/TOutput.cpp
index 800ba07..a30879a 100644
--- a/lib/cpp/src/thrift/TOutput.cpp
+++ b/lib/cpp/src/thrift/TOutput.cpp
@@ -122,8 +122,8 @@
 #else // HAVE_STRERROR_R
 #ifdef _WIN32
   const size_t size = FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
-                                     NULL, errno_copy, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-                                     b_errbuf, sizeof(b_errbuf), NULL);
+                                     nullptr, errno_copy, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                                     b_errbuf, sizeof(b_errbuf), nullptr);
 
   if (size > 2 && b_errbuf[size-2] == '\r' && b_errbuf[size-1] == '\n') {
     b_errbuf[size-2] = '\0';
diff --git a/lib/cpp/src/thrift/VirtualProfiling.cpp b/lib/cpp/src/thrift/VirtualProfiling.cpp
index 6ce346b..4d752cf 100644
--- a/lib/cpp/src/thrift/VirtualProfiling.cpp
+++ b/lib/cpp/src/thrift/VirtualProfiling.cpp
@@ -112,7 +112,7 @@
   void* getFrame(int index) const {
     int adjusted_index = index + skip_;
     if (adjusted_index < 0 || adjusted_index >= numCallers_) {
-      return NULL;
+      return nullptr;
     }
     return callers_[adjusted_index];
   }
@@ -151,7 +151,7 @@
   };
 
   Key(const Backtrace* bt, const std::type_info& type_info)
-    : backtrace_(bt), typeName1_(type_info.name()), typeName2_(NULL) {}
+    : backtrace_(bt), typeName1_(type_info.name()), typeName2_(nullptr) {}
 
   Key(const Backtrace* bt, const std::type_info& type_info1, const std::type_info& type_info2)
     : backtrace_(bt), typeName1_(type_info1.name()), typeName2_(type_info2.name()) {}
@@ -189,7 +189,7 @@
    */
   void cleanup() {
     delete backtrace_;
-    backtrace_ = NULL;
+    backtrace_ = nullptr;
   }
 
   int cmp(const Key& k) const {
diff --git a/lib/cpp/src/thrift/server/TNonblockingServer.cpp b/lib/cpp/src/thrift/server/TNonblockingServer.cpp
index 26ffa68..ea394c8 100644
--- a/lib/cpp/src/thrift/server/TNonblockingServer.cpp
+++ b/lib/cpp/src/thrift/server/TNonblockingServer.cpp
@@ -1341,7 +1341,7 @@
     FD_ZERO(&efds);
     FD_SET(fd, &wfds);
     FD_SET(fd, &efds);
-    ret = select(static_cast<int>(fd + 1), NULL, &wfds, &efds, NULL);
+    ret = select(static_cast<int>(fd + 1), nullptr, &wfds, &efds, nullptr);
     if (ret < 0) {
       return false;
     } else if (ret == 0) {
diff --git a/lib/cpp/src/thrift/server/TNonblockingServer.h b/lib/cpp/src/thrift/server/TNonblockingServer.h
index e44c7ee..65e569d 100644
--- a/lib/cpp/src/thrift/server/TNonblockingServer.h
+++ b/lib/cpp/src/thrift/server/TNonblockingServer.h
@@ -158,7 +158,7 @@
   /// The optional user-provided event-base (for single-thread servers)
   event_base* userEventBase_;
 
-  /// For processing via thread pool, may be NULL
+  /// For processing via thread pool, may be nullptr
   std::shared_ptr<ThreadManager> threadManager_;
 
   /// Is thread pool processing?
diff --git a/lib/cpp/src/thrift/transport/TBufferTransports.cpp b/lib/cpp/src/thrift/transport/TBufferTransports.cpp
index 329d220..d8a1b3e 100644
--- a/lib/cpp/src/thrift/transport/TBufferTransports.cpp
+++ b/lib/cpp/src/thrift/transport/TBufferTransports.cpp
@@ -112,7 +112,7 @@
 const uint8_t* TBufferedTransport::borrowSlow(uint8_t* buf, uint32_t* len) {
   (void)buf;
   (void)len;
-  // Simply return NULL.  We don't know if there is actually data available on
+  // Simply return nullptr.  We don't know if there is actually data available on
   // the underlying transport, so calling read() might block.
   return nullptr;
 }
diff --git a/lib/cpp/src/thrift/transport/TBufferTransports.h b/lib/cpp/src/thrift/transport/TBufferTransports.h
index df06586..86f0c5a 100644
--- a/lib/cpp/src/thrift/transport/TBufferTransports.h
+++ b/lib/cpp/src/thrift/transport/TBufferTransports.h
@@ -137,7 +137,7 @@
   /**
    * Slow path borrow.
    *
-   * POSTCONDITION: return == NULL || rBound_ - rBase_ >= *len
+   * POSTCONDITION: return == nullptr || rBound_ - rBase_ >= *len
    */
   virtual const uint8_t* borrowSlow(uint8_t* buf, uint32_t* len) = 0;
 
@@ -245,7 +245,7 @@
   /**
    * The following behavior is currently implemented by TBufferedTransport,
    * but that may change in a future version:
-   * 1/ If len is at most rBufSize_, borrow will never return NULL.
+   * 1/ If len is at most rBufSize_, borrow will never return nullptr.
    *    Depending on the underlying transport, it could throw an exception
    *    or hang forever.
    * 2/ Some borrow requests may copy bytes internally.  However,
diff --git a/lib/cpp/src/thrift/transport/TNonblockingServerTransport.h b/lib/cpp/src/thrift/transport/TNonblockingServerTransport.h
index f811328..e8997d7 100644
--- a/lib/cpp/src/thrift/transport/TNonblockingServerTransport.h
+++ b/lib/cpp/src/thrift/transport/TNonblockingServerTransport.h
@@ -49,7 +49,7 @@
    * Gets a new dynamically allocated transport object and passes it to the
    * caller. Note that it is the explicit duty of the caller to free the
    * allocated object. The returned TTransport object must always be in the
-   * opened state. NULL should never be returned, instead an Exception should
+   * opened state. nullptr should never be returned, instead an Exception should
    * always be thrown.
    *
    * @return A new TTransport object
@@ -58,7 +58,7 @@
   std::shared_ptr<TSocket> accept() {
     std::shared_ptr<TSocket> result = acceptImpl();
     if (!result) {
-      throw TTransportException("accept() may not return NULL");
+      throw TTransportException("accept() may not return nullptr");
     }
     return result;
   }
diff --git a/lib/cpp/src/thrift/transport/TPipe.cpp b/lib/cpp/src/thrift/transport/TPipe.cpp
index 72af4fc..4c2fea9 100644
--- a/lib/cpp/src/thrift/transport/TPipe.cpp
+++ b/lib/cpp/src/thrift/transport/TPipe.cpp
@@ -183,7 +183,7 @@
 
   uint32_t written = 0;
   while (written < len) {
-    BOOL result = ::WriteFile(pipe, buf + written, len - written, NULL, &tempOverlap);
+    BOOL result = ::WriteFile(pipe, buf + written, len - written, nullptr, &tempOverlap);
 
     if (result == FALSE && ::GetLastError() != ERROR_IO_PENDING) {
       GlobalOutput.perror("TPipe ::WriteFile errored GLE=", ::GetLastError());
@@ -205,7 +205,7 @@
   memset(&tempOverlap, 0, sizeof(tempOverlap));
   tempOverlap.hEvent = event;
 
-  BOOL result = ::ReadFile(pipe, buf, len, NULL, &tempOverlap);
+  BOOL result = ::ReadFile(pipe, buf, len, nullptr, &tempOverlap);
 
   if (result == FALSE && ::GetLastError() != ERROR_IO_PENDING) {
     GlobalOutput.perror("TPipe ::ReadFile errored GLE=", ::GetLastError());
@@ -255,7 +255,7 @@
 // Transport callbacks
 //---------------------------------------------------------
 bool TPipe::isOpen() const {
-  return impl_.get() != NULL;
+  return impl_.get() != nullptr;
 }
 
 bool TPipe::peek() {
@@ -272,10 +272,10 @@
     hPipe.reset(CreateFileA(pipename_.c_str(),
                             GENERIC_READ | GENERIC_WRITE,
                             0,             // no sharing
-                            NULL,          // default security attributes
+                            nullptr,          // default security attributes
                             OPEN_EXISTING, // opens existing pipe
                             flags,
-                            NULL)); // no template file
+                            nullptr)); // no template file
 
     if (hPipe.h != INVALID_HANDLE_VALUE)
       break; // success!
@@ -310,7 +310,7 @@
                           buf,     // buffer to receive reply
                           len,     // size of buffer
                           &cbRead, // number of bytes read
-                          NULL);   // not overlapped
+                          nullptr);   // not overlapped
 
   if (!fSuccess && GetLastError() != ERROR_MORE_DATA)
     return 0; // No more data, possibly because client disconnected.
@@ -330,7 +330,7 @@
                            buf,        // message
                            len,        // message length
                            &cbWritten, // bytes written
-                           NULL);      // not overlapped
+                           nullptr);      // not overlapped
 
   if (!fSuccess)
     throw TTransportException(TTransportException::NOT_OPEN, "Write to pipe failed");
diff --git a/lib/cpp/src/thrift/transport/TPipeServer.cpp b/lib/cpp/src/thrift/transport/TPipeServer.cpp
index e1cee80..2763551 100644
--- a/lib/cpp/src/thrift/transport/TPipeServer.cpp
+++ b/lib/cpp/src/thrift/transport/TPipeServer.cpp
@@ -50,7 +50,7 @@
   virtual HANDLE getWrtPipeHandle() = 0;
   virtual HANDLE getClientRdPipeHandle() = 0;
   virtual HANDLE getClientWrtPipeHandle() = 0;
-  virtual HANDLE getNativeWaitHandle() { return NULL; }
+  virtual HANDLE getNativeWaitHandle() { return nullptr; }
 };
 
 class TAnonPipeServer : public TPipeServerImpl {
@@ -155,7 +155,7 @@
 HANDLE TPipeServer::getNativeWaitHandle() {
   if (impl_)
     return impl_->getNativeWaitHandle();
-  return NULL;
+  return nullptr;
 }
 
 //---- Constructors ----
@@ -227,7 +227,7 @@
                           &buf,     // buffer to receive reply
                           0,        // size of buffer
                           &br,      // number of bytes read
-                          NULL);    // not overlapped
+                          nullptr);    // not overlapped
 
   if (!fSuccess && GetLastError() != ERROR_MORE_DATA) {
     GlobalOutput.perror("TPipeServer unable to initiate pipe comms, GLE=", GetLastError());
@@ -248,7 +248,7 @@
 
   // The prior connection has been handled, so close the gate
   ResetEvent(listen_event_.h);
-  connectOverlap_.reset(NULL, 0, listen_event_.h);
+  connectOverlap_.reset(nullptr, 0, listen_event_.h);
   connectOverlap_.h = Pipe_.h;
   thread_->addWorkItem(&connectOverlap_);
 
@@ -283,7 +283,7 @@
 shared_ptr<TTransport> TNamedPipeServer::acceptImpl() {
   {
     TAutoCrit lock(pipe_protect_);
-    if (cached_client_.get() != NULL) {
+    if (cached_client_.get() != nullptr) {
       shared_ptr<TPipe> client;
       // zero out cached_client, since we are about to return it.
       client.swap(cached_client_);
@@ -350,7 +350,7 @@
 
 bool TNamedPipeServer::createNamedPipe(const TAutoCrit& /*lockProof*/) {
 
-  PSECURITY_DESCRIPTOR psd = NULL;
+  PSECURITY_DESCRIPTOR psd = nullptr;
   ULONG size = 0;
 
   if (!ConvertStringSecurityDescriptorToSecurityDescriptorA(securityDescriptor_.c_str(),
@@ -404,7 +404,7 @@
                         GetLastError());
     return false;
   }
-  if (!SetSecurityDescriptorDacl(&sd, true, NULL, false)) {
+  if (!SetSecurityDescriptorDacl(&sd, true, nullptr, false)) {
     GlobalOutput.perror("TPipeServer SetSecurityDescriptorDacl (anon) failed, GLE=",
                         GetLastError());
     return false;
diff --git a/lib/cpp/src/thrift/transport/TSSLSocket.cpp b/lib/cpp/src/thrift/transport/TSSLSocket.cpp
index 64f08dd..aa76980 100644
--- a/lib/cpp/src/thrift/transport/TSSLSocket.cpp
+++ b/lib/cpp/src/thrift/transport/TSSLSocket.cpp
@@ -562,7 +562,7 @@
     throw TSSLException("BIO_flush: Handshake is not completed");
   BIO* bio = SSL_get_wbio(ssl_);
   if (bio == nullptr) {
-    throw TSSLException("SSL_get_wbio returns NULL");
+    throw TSSLException("SSL_get_wbio returns nullptr");
   }
   if (BIO_flush(bio) != 1) {
     int errno_copy = THRIFT_GET_SOCKET_ERROR;
@@ -798,7 +798,7 @@
   }
 
   if (bio == nullptr) {
-    throw TSSLException("SSL_get_?bio returned NULL");
+    throw TSSLException("SSL_get_?bio returned nullptr");
   }
 
   if (BIO_get_fd(bio, &fdSocket) <= 0) {
@@ -943,7 +943,7 @@
 void TSSLSocketFactory::loadCertificate(const char* path, const char* format) {
   if (path == nullptr || format == nullptr) {
     throw TTransportException(TTransportException::BAD_ARGS,
-                              "loadCertificateChain: either <path> or <format> is NULL");
+                              "loadCertificateChain: either <path> or <format> is nullptr");
   }
   if (strcmp(format, "PEM") == 0) {
     if (SSL_CTX_use_certificate_chain_file(ctx_->get(), path) == 0) {
@@ -960,12 +960,12 @@
 void TSSLSocketFactory::loadCertificateFromBuffer(const char* aCertificate, const char* format) {
   if (aCertificate == nullptr || format == nullptr) {
     throw TTransportException(TTransportException::BAD_ARGS,
-                              "loadCertificate: either <path> or <format> is NULL");
+                              "loadCertificate: either <path> or <format> is nullptr");
   }
   if (strcmp(format, "PEM") == 0) {
     BIO* mem = BIO_new(BIO_s_mem());
     BIO_puts(mem, aCertificate);
-    X509* cert = PEM_read_bio_X509(mem, NULL, 0, NULL);
+    X509* cert = PEM_read_bio_X509(mem, nullptr, 0, nullptr);
     BIO_free(mem);
 
     if (SSL_CTX_use_certificate(ctx_->get(), cert) == 0) {
@@ -982,7 +982,7 @@
 void TSSLSocketFactory::loadPrivateKey(const char* path, const char* format) {
   if (path == nullptr || format == nullptr) {
     throw TTransportException(TTransportException::BAD_ARGS,
-                              "loadPrivateKey: either <path> or <format> is NULL");
+                              "loadPrivateKey: either <path> or <format> is nullptr");
   }
   if (strcmp(format, "PEM") == 0) {
     if (SSL_CTX_use_PrivateKey_file(ctx_->get(), path, SSL_FILETYPE_PEM) == 0) {
@@ -997,7 +997,7 @@
 void TSSLSocketFactory::loadPrivateKeyFromBuffer(const char* aPrivateKey, const char* format) {
   if (aPrivateKey == nullptr || format == nullptr) {
     throw TTransportException(TTransportException::BAD_ARGS,
-                              "loadPrivateKey: either <path> or <format> is NULL");
+                              "loadPrivateKey: either <path> or <format> is nullptr");
   }
   if (strcmp(format, "PEM") == 0) {
     BIO* mem = BIO_new(BIO_s_mem());
@@ -1019,7 +1019,7 @@
 void TSSLSocketFactory::loadTrustedCertificates(const char* path, const char* capath) {
   if (path == nullptr) {
     throw TTransportException(TTransportException::BAD_ARGS,
-                              "loadTrustedCertificates: <path> is NULL");
+                              "loadTrustedCertificates: <path> is nullptr");
   }
   if (SSL_CTX_load_verify_locations(ctx_->get(), path, capath) == 0) {
     int errno_copy = THRIFT_GET_SOCKET_ERROR;
@@ -1037,7 +1037,7 @@
   X509_STORE* vX509Store = SSL_CTX_get_cert_store(ctx_->get());
   BIO* mem = BIO_new(BIO_s_mem());
   BIO_puts(mem, aCertificate);
-  X509* cert = PEM_read_bio_X509(mem, NULL, 0, NULL);
+  X509* cert = PEM_read_bio_X509(mem, nullptr, 0, nullptr);
   BIO_free(mem);
 
   if (X509_STORE_add_cert(vX509Store, cert) == 0) {
@@ -1050,7 +1050,7 @@
   if (aChain) {
     mem = BIO_new(BIO_s_mem());
     BIO_puts(mem, aChain);
-    cert = PEM_read_bio_X509(mem, NULL, 0, NULL);
+    cert = PEM_read_bio_X509(mem, nullptr, 0, nullptr);
     BIO_free(mem);
 
     if (SSL_CTX_add_extra_chain_cert(ctx_->get(), cert) == 0) {
diff --git a/lib/cpp/src/thrift/transport/TServerTransport.h b/lib/cpp/src/thrift/transport/TServerTransport.h
index 9e84850..0c56609 100644
--- a/lib/cpp/src/thrift/transport/TServerTransport.h
+++ b/lib/cpp/src/thrift/transport/TServerTransport.h
@@ -54,7 +54,7 @@
    * Gets a new dynamically allocated transport object and passes it to the
    * caller. Note that it is the explicit duty of the caller to free the
    * allocated object. The returned TTransport object must always be in the
-   * opened state. NULL should never be returned, instead an Exception should
+   * opened state. nullptr should never be returned, instead an Exception should
    * always be thrown.
    *
    * @return A new TTransport object
@@ -63,7 +63,7 @@
   std::shared_ptr<TTransport> accept() {
     std::shared_ptr<TTransport> result = acceptImpl();
     if (!result) {
-      throw TTransportException("accept() may not return NULL");
+      throw TTransportException("accept() may not return nullptr");
     }
     return result;
   }
diff --git a/lib/cpp/src/thrift/transport/TSocket.cpp b/lib/cpp/src/thrift/transport/TSocket.cpp
index 3811279..a1a6dfb 100644
--- a/lib/cpp/src/thrift/transport/TSocket.cpp
+++ b/lib/cpp/src/thrift/transport/TSocket.cpp
@@ -432,7 +432,7 @@
 
 void TSocket::unix_open() {
   if (!path_.empty()) {
-    // Unix Domain SOcket does not need addrinfo struct, so we pass NULL
+    // Unix Domain SOcket does not need addrinfo struct, so we pass nullptr
     openConnection(nullptr);
   }
 }
diff --git a/lib/cpp/src/thrift/transport/TTransport.h b/lib/cpp/src/thrift/transport/TTransport.h
index 891bfe1..6397882 100644
--- a/lib/cpp/src/thrift/transport/TTransport.h
+++ b/lib/cpp/src/thrift/transport/TTransport.h
@@ -191,7 +191,7 @@
    * @oaram buf  A buffer where the data can be stored if needed.
    *             If borrow doesn't return buf, then the contents of
    *             buf after the call are undefined.  This parameter may be
-   *             NULL to indicate that the caller is not supplying storage,
+   *             nullptr to indicate that the caller is not supplying storage,
    *             but would like a pointer into an internal buffer, if
    *             available.
    * @param len  *len should initially contain the number of bytes to borrow.
diff --git a/lib/cpp/src/thrift/windows/GetTimeOfDay.cpp b/lib/cpp/src/thrift/windows/GetTimeOfDay.cpp
index 0a0292c..ac24124 100644
--- a/lib/cpp/src/thrift/windows/GetTimeOfDay.cpp
+++ b/lib/cpp/src/thrift/windows/GetTimeOfDay.cpp
@@ -51,7 +51,7 @@
 int thrift_gettimeofday(struct timeval * tp, struct timezone * tzp)
 {
     // We don't fill it in so prove nobody is looking for the data
-    assert(tzp == NULL);
+    assert(tzp == nullptr);
 
     // Note: some broken versions only have 8 trailing zero's, the correct epoch has 9 trailing zero's
     // This magic number is the number of 100 nanosecond intervals since January 1, 1601 (UTC)
diff --git a/lib/cpp/src/thrift/windows/SocketPair.cpp b/lib/cpp/src/thrift/windows/SocketPair.cpp
index 7228832..2650b37 100644
--- a/lib/cpp/src/thrift/windows/SocketPair.cpp
+++ b/lib/cpp/src/thrift/windows/SocketPair.cpp
@@ -77,12 +77,12 @@
       break;
     if (listen(listener, 1) == SOCKET_ERROR)
       break;
-    sv[0] = WSASocket(AF_INET, SOCK_STREAM, 0, NULL, 0, flags);
+    sv[0] = WSASocket(AF_INET, SOCK_STREAM, 0, nullptr, 0, flags);
     if (sv[0] == INVALID_SOCKET)
       break;
     if (connect(sv[0], &a.addr, sizeof(a.inaddr)) == SOCKET_ERROR)
       break;
-    sv[1] = accept(listener, NULL, NULL);
+    sv[1] = accept(listener, nullptr, nullptr);
     if (sv[1] == INVALID_SOCKET)
       break;
 
diff --git a/lib/cpp/src/thrift/windows/Sync.h b/lib/cpp/src/thrift/windows/Sync.h
index 5d32199..a296d7e 100644
--- a/lib/cpp/src/thrift/windows/Sync.h
+++ b/lib/cpp/src/thrift/windows/Sync.h
@@ -55,8 +55,8 @@
   HANDLE h;
 
   TAutoResetEvent() {
-    h = CreateEvent(NULL, FALSE, FALSE, NULL);
-    if (h == NULL) {
+    h = CreateEvent(nullptr, FALSE, FALSE, nullptr);
+    if (h == nullptr) {
       GlobalOutput.perror("TAutoResetEvent unable to create event, GLE=", GetLastError());
       throw apache::thrift::concurrency::SystemResourceException("CreateEvent failed");
     }
@@ -68,8 +68,8 @@
   HANDLE h;
 
   TManualResetEvent() {
-    h = CreateEvent(NULL, TRUE, FALSE, NULL);
-    if (h == NULL) {
+    h = CreateEvent(nullptr, TRUE, FALSE, nullptr);
+    if (h == nullptr) {
       GlobalOutput.perror("TManualResetEvent unable to create event, GLE=", GetLastError());
       throw apache::thrift::concurrency::SystemResourceException("CreateEvent failed");
     }
diff --git a/lib/cpp/src/thrift/windows/TWinsockSingleton.cpp b/lib/cpp/src/thrift/windows/TWinsockSingleton.cpp
index a502cbd..c3339f3 100644
--- a/lib/cpp/src/thrift/windows/TWinsockSingleton.cpp
+++ b/lib/cpp/src/thrift/windows/TWinsockSingleton.cpp
@@ -26,7 +26,7 @@
 namespace thrift {
 namespace transport {
 
-TWinsockSingleton::instance_ptr TWinsockSingleton::instance_ptr_(NULL);
+TWinsockSingleton::instance_ptr TWinsockSingleton::instance_ptr_(nullptr);
 std::once_flag TWinsockSingleton::flags_;
 
 //------------------------------------------------------------------------------
diff --git a/lib/cpp/src/thrift/windows/WinFcntl.cpp b/lib/cpp/src/thrift/windows/WinFcntl.cpp
index c907e92..292ddfc 100644
--- a/lib/cpp/src/thrift/windows/WinFcntl.cpp
+++ b/lib/cpp/src/thrift/windows/WinFcntl.cpp
@@ -45,8 +45,8 @@
 #if WINVER <= 0x0502 // XP, Server2003
 int thrift_poll(THRIFT_POLLFD* fdArray, ULONG nfds, INT timeout) {
   fd_set read_fds, write_fds;
-  fd_set* read_fds_ptr = NULL;
-  fd_set* write_fds_ptr = NULL;
+  fd_set* read_fds_ptr = nullptr;
+  fd_set* write_fds_ptr = nullptr;
 
   FD_ZERO(&read_fds);
   FD_ZERO(&write_fds);
@@ -65,7 +65,7 @@
   }
 
   timeval time_out;
-  timeval* time_out_ptr = NULL;
+  timeval* time_out_ptr = nullptr;
   if (timeout >= 0) {
     time_out.tv_sec = timeout / 1000;
     time_out.tv_usec = (timeout % 1000) * 1000;
@@ -75,7 +75,7 @@
     (void)timeout;
   }
 
-  int sktready = select(1, read_fds_ptr, write_fds_ptr, NULL, time_out_ptr);
+  int sktready = select(1, read_fds_ptr, write_fds_ptr, nullptr, time_out_ptr);
   if (sktready > 0) {
     for (ULONG i = 0; i < nfds; i++) {
       fdArray[i].revents = 0;
diff --git a/lib/cpp/test/OpenSSLManualInitTest.cpp b/lib/cpp/test/OpenSSLManualInitTest.cpp
index a751806..935a205 100644
--- a/lib/cpp/test/OpenSSLManualInitTest.cpp
+++ b/lib/cpp/test/OpenSSLManualInitTest.cpp
@@ -88,6 +88,6 @@
 
   suite->add(BOOST_TEST_CASE(test_openssl_availability));
 
-  return NULL;
+  return nullptr;
 }
 #endif
\ No newline at end of file
diff --git a/lib/cpp/test/TFileTransportTest.cpp b/lib/cpp/test/TFileTransportTest.cpp
index 21c1f3b..c116fdc 100644
--- a/lib/cpp/test/TFileTransportTest.cpp
+++ b/lib/cpp/test/TFileTransportTest.cpp
@@ -399,6 +399,6 @@
 
   // Parse arguments
   parse_args(argc, argv);
-  return NULL;
+  return nullptr;
 }
 #endif
diff --git a/lib/cpp/test/TransportTest.cpp b/lib/cpp/test/TransportTest.cpp
index a890aa8..085197a 100644
--- a/lib/cpp/test/TransportTest.cpp
+++ b/lib/cpp/test/TransportTest.cpp
@@ -230,7 +230,7 @@
   HANDLE hWrite;
 
   CoupledPipeTransports() {
-    BOOST_REQUIRE(CreatePipe(&hRead, &hWrite, NULL, 1048576 * 2));
+    BOOST_REQUIRE(CreatePipe(&hRead, &hWrite, nullptr, 1048576 * 2));
     in.reset(new TPipe(hRead, hWrite));
     in->open();
     out = in;
@@ -707,7 +707,7 @@
   uint8_t read_buf[16];
   memset(write_buf, 'a', sizeof(write_buf));
 
-  // Attemping to borrow 10 bytes when only 9 are available should return NULL
+  // Attemping to borrow 10 bytes when only 9 are available should return nullptr
   // immediately.
   transports.out->write(write_buf, 9);
   transports.out->flush();
@@ -1075,7 +1075,7 @@
   THRIFT_UNUSED_VARIABLE(argc);
   THRIFT_UNUSED_VARIABLE(argv);
   struct timeval tv;
-  THRIFT_GETTIMEOFDAY(&tv, NULL);
+  THRIFT_GETTIMEOFDAY(&tv, nullptr);
   int seed = tv.tv_sec ^ tv.tv_usec;
 
   initrand(seed);
@@ -1084,6 +1084,6 @@
   suite->p_name.value = "TransportTest";
   TransportTestGen transport_test_generator(suite, 1);
   transport_test_generator.generate();
-  return NULL;
+  return nullptr;
 }
 #endif
diff --git a/lib/cpp/test/ZlibTest.cpp b/lib/cpp/test/ZlibTest.cpp
index 3e2eb81..274a243 100644
--- a/lib/cpp/test/ZlibTest.cpp
+++ b/lib/cpp/test/ZlibTest.cpp
@@ -454,7 +454,7 @@
 boost::unit_test::test_suite* init_unit_test_suite(int argc, char* argv[]) {
   THRIFT_UNUSED_VARIABLE(argc);
   THRIFT_UNUSED_VARIABLE(argv);
-  uint32_t seed = static_cast<uint32_t>(time(NULL));
+  uint32_t seed = static_cast<uint32_t>(time(nullptr));
 #ifdef HAVE_INTTYPES_H
   printf("seed: %" PRIu32 "\n", seed);
 #endif
@@ -470,6 +470,6 @@
 
   suite->add(BOOST_TEST_CASE(test_no_write));
 
-  return NULL;
+  return nullptr;
 }
 #endif
diff --git a/lib/cpp/test/processor/ProcessorTest.cpp b/lib/cpp/test/processor/ProcessorTest.cpp
index a36ef3e..017fa89 100644
--- a/lib/cpp/test/processor/ProcessorTest.cpp
+++ b/lib/cpp/test/processor/ProcessorTest.cpp
@@ -924,6 +924,6 @@
   THRIFT_UNUSED_VARIABLE(argc);
   THRIFT_UNUSED_VARIABLE(argv);
   ::boost::unit_test::framework::master_test_suite().p_name.value = "ProcessorTest";
-  return NULL;
+  return nullptr;
 }
 #endif
diff --git a/lib/php/src/ext/thrift_protocol/php_thrift_protocol.cpp b/lib/php/src/ext/thrift_protocol/php_thrift_protocol.cpp
index e152d08..c8bc50e 100644
--- a/lib/php/src/ext/thrift_protocol/php_thrift_protocol.cpp
+++ b/lib/php/src/ext/thrift_protocol/php_thrift_protocol.cpp
@@ -414,7 +414,7 @@
   object_and_properties_init(return_value, ce, nullptr);
   zend_function* constructor = zend_std_get_constructor(Z_OBJ_P(return_value));
   zval ctor_rv;
-  zend_call_method(return_value, ce, &constructor, NULL, 0, &ctor_rv, nargs, arg1, arg2);
+  zend_call_method(return_value, ce, &constructor, nullptr, 0, &ctor_rv, nargs, arg1, arg2);
   zval_dtor(&ctor_rv);
   if (EG(exception)) {
     zend_object *ex = EG(exception);
diff --git a/lib/py/src/ext/module.cpp b/lib/py/src/ext/module.cpp
index 7158b8f..f14ddae 100644
--- a/lib/py/src/ext/module.cpp
+++ b/lib/py/src/ext/module.cpp
@@ -48,20 +48,20 @@
 template <typename T>
 static PyObject* encode_impl(PyObject* args) {
   if (!args)
-    return NULL;
+    return nullptr;
 
-  PyObject* enc_obj = NULL;
-  PyObject* type_args = NULL;
+  PyObject* enc_obj = nullptr;
+  PyObject* type_args = nullptr;
   if (!PyArg_ParseTuple(args, "OO", &enc_obj, &type_args)) {
-    return NULL;
+    return nullptr;
   }
   if (!enc_obj || !type_args) {
-    return NULL;
+    return nullptr;
   }
 
   T protocol;
   if (!protocol.prepareEncodeBuffer() || !protocol.encodeValue(enc_obj, T_STRUCT, type_args)) {
-    return NULL;
+    return nullptr;
   }
 
   return protocol.getEncodedValue();
@@ -79,11 +79,11 @@
 
 template <typename T>
 static PyObject* decode_impl(PyObject* args) {
-  PyObject* output_obj = NULL;
-  PyObject* oprot = NULL;
-  PyObject* typeargs = NULL;
+  PyObject* output_obj = nullptr;
+  PyObject* oprot = nullptr;
+  PyObject* typeargs = nullptr;
   if (!PyArg_ParseTuple(args, "OOO", &output_obj, &oprot, &typeargs)) {
-    return NULL;
+    return nullptr;
   }
 
   T protocol;
@@ -96,16 +96,16 @@
                           default_limit));
   ScopedPyObject transport(PyObject_GetAttr(oprot, INTERN_STRING(trans)));
   if (!transport) {
-    return NULL;
+    return nullptr;
   }
 
   StructTypeArgs parsedargs;
   if (!parse_struct_args(&parsedargs, typeargs)) {
-    return NULL;
+    return nullptr;
   }
 
   if (!protocol.prepareDecodeBufferFromTransport(transport.get())) {
-    return NULL;
+    return nullptr;
   }
 
   return protocol.readStruct(output_obj, parsedargs.klass, parsedargs.spec);
@@ -141,22 +141,22 @@
     {"decode_binary", decode_binary, METH_VARARGS, ""},
     {"encode_compact", encode_compact, METH_VARARGS, ""},
     {"decode_compact", decode_compact, METH_VARARGS, ""},
-    {NULL, NULL, 0, NULL} /* Sentinel */
+    {nullptr, nullptr, 0, nullptr} /* Sentinel */
 };
 
 #if PY_MAJOR_VERSION >= 3
 
 static struct PyModuleDef ThriftFastBinaryDef = {PyModuleDef_HEAD_INIT,
                                                  "thrift.protocol.fastbinary",
-                                                 NULL,
+                                                 nullptr,
                                                  0,
                                                  ThriftFastBinaryMethods,
-                                                 NULL,
-                                                 NULL,
-                                                 NULL,
-                                                 NULL};
+                                                 nullptr,
+                                                 nullptr,
+                                                 nullptr,
+                                                 nullptr};
 
-#define INITERROR return NULL;
+#define INITERROR return nullptr;
 
 PyObject* PyInit_fastbinary() {
 
@@ -167,7 +167,7 @@
 void initfastbinary() {
 
   PycString_IMPORT;
-  if (PycStringIO == NULL)
+  if (PycStringIO == nullptr)
     INITERROR
 
 #endif
@@ -193,7 +193,7 @@
 #else
       Py_InitModule("thrift.protocol.fastbinary", ThriftFastBinaryMethods);
 #endif
-  if (module == NULL)
+  if (module == nullptr)
     INITERROR;
 
 #if PY_MAJOR_VERSION >= 3
diff --git a/lib/py/src/ext/protocol.h b/lib/py/src/ext/protocol.h
index 521b7ee..c0cd437 100644
--- a/lib/py/src/ext/protocol.h
+++ b/lib/py/src/ext/protocol.h
@@ -35,7 +35,7 @@
   ProtocolBase()
     : stringLimit_((std::numeric_limits<int32_t>::max)()),
       containerLimit_((std::numeric_limits<int32_t>::max)()),
-      output_(NULL) {}
+      output_(nullptr) {}
   inline virtual ~ProtocolBase();
 
   bool prepareDecodeBufferFromTransport(PyObject* trans);
diff --git a/lib/py/src/ext/protocol.tcc b/lib/py/src/ext/protocol.tcc
index ede2bb4..03cfc9b 100644
--- a/lib/py/src/ext/protocol.tcc
+++ b/lib/py/src/ext/protocol.tcc
@@ -48,7 +48,7 @@
     PycString_IMPORT;
   }
   if (!PycStringIO) {
-    return NULL;
+    return nullptr;
   }
   return PycStringIO->NewOutput(size);
 }
@@ -83,7 +83,7 @@
     PycString_IMPORT;
   }
   if (!PycStringIO) {
-    return NULL;
+    return nullptr;
   }
   return PycStringIO->cgetvalue(output_);
 }
@@ -277,7 +277,7 @@
   } else {
     // using building functions as this is a rare codepath
     ScopedPyObject newiobuf(PyObject_CallFunction(input_.refill_callable.get(), refill_signature,
-                                                  *output, rlen, len, NULL));
+                                                  *output, rlen, len, nullptr));
     if (!newiobuf) {
       return false;
     }
@@ -332,7 +332,7 @@
 template <typename Impl>
 bool ProtocolBase<Impl>::prepareEncodeBuffer() {
   output_ = detail::new_encode_buffer(INIT_OUTBUF_SIZE);
-  return output_ != NULL;
+  return output_ != nullptr;
 }
 
 template <typename Impl>
@@ -484,8 +484,8 @@
       return false;
     }
     Py_ssize_t pos = 0;
-    PyObject* k = NULL;
-    PyObject* v = NULL;
+    PyObject* k = nullptr;
+    PyObject* v = nullptr;
     // TODO(bmaurer): should support any mapping, not just dicts
     while (PyDict_Next(value, &pos, &k, &v)) {
       if (!encodeValue(k, parsedargs.ktag, parsedargs.ktypeargs)
@@ -647,7 +647,7 @@
   case T_BOOL: {
     bool v = 0;
     if (!impl()->readBool(v)) {
-      return NULL;
+      return nullptr;
     }
     if (v) {
       Py_RETURN_TRUE;
@@ -658,21 +658,21 @@
   case T_I08: {
     int8_t v = 0;
     if (!impl()->readI8(v)) {
-      return NULL;
+      return nullptr;
     }
     return PyInt_FromLong(v);
   }
   case T_I16: {
     int16_t v = 0;
     if (!impl()->readI16(v)) {
-      return NULL;
+      return nullptr;
     }
     return PyInt_FromLong(v);
   }
   case T_I32: {
     int32_t v = 0;
     if (!impl()->readI32(v)) {
-      return NULL;
+      return nullptr;
     }
     return PyInt_FromLong(v);
   }
@@ -680,7 +680,7 @@
   case T_I64: {
     int64_t v = 0;
     if (!impl()->readI64(v)) {
-      return NULL;
+      return nullptr;
     }
     // TODO(dreiss): Find out if we can take this fastpath always when
     //               sizeof(long) == sizeof(long long).
@@ -693,16 +693,16 @@
   case T_DOUBLE: {
     double v = 0.0;
     if (!impl()->readDouble(v)) {
-      return NULL;
+      return nullptr;
     }
     return PyFloat_FromDouble(v);
   }
 
   case T_STRING: {
-    char* buf = NULL;
+    char* buf = nullptr;
     int len = impl()->readString(&buf);
     if (len < 0) {
-      return NULL;
+      return nullptr;
     }
     if (isUtf8(typeargs)) {
       return PyUnicode_DecodeUTF8(buf, len, 0);
@@ -715,28 +715,28 @@
   case T_SET: {
     SetListTypeArgs parsedargs;
     if (!parse_set_list_args(&parsedargs, typeargs)) {
-      return NULL;
+      return nullptr;
     }
 
     TType etype = T_STOP;
     int32_t len = impl()->readListBegin(etype);
     if (len < 0) {
-      return NULL;
+      return nullptr;
     }
     if (len > 0 && !checkType(etype, parsedargs.element_type)) {
-      return NULL;
+      return nullptr;
     }
 
     bool use_tuple = type == T_LIST && parsedargs.immutable;
     ScopedPyObject ret(use_tuple ? PyTuple_New(len) : PyList_New(len));
     if (!ret) {
-      return NULL;
+      return nullptr;
     }
 
     for (int i = 0; i < len; i++) {
       PyObject* item = decodeValue(etype, parsedargs.typeargs);
       if (!item) {
-        return NULL;
+        return nullptr;
       }
       if (use_tuple) {
         PyTuple_SET_ITEM(ret.get(), i, item);
@@ -758,32 +758,32 @@
   case T_MAP: {
     MapTypeArgs parsedargs;
     if (!parse_map_args(&parsedargs, typeargs)) {
-      return NULL;
+      return nullptr;
     }
 
     TType ktype = T_STOP;
     TType vtype = T_STOP;
     uint32_t len = impl()->readMapBegin(ktype, vtype);
     if (len > 0 && (!checkType(ktype, parsedargs.ktag) || !checkType(vtype, parsedargs.vtag))) {
-      return NULL;
+      return nullptr;
     }
 
     ScopedPyObject ret(PyDict_New());
     if (!ret) {
-      return NULL;
+      return nullptr;
     }
 
     for (uint32_t i = 0; i < len; i++) {
       ScopedPyObject k(decodeValue(ktype, parsedargs.ktypeargs));
       if (!k) {
-        return NULL;
+        return nullptr;
       }
       ScopedPyObject v(decodeValue(vtype, parsedargs.vtypeargs));
       if (!v) {
-        return NULL;
+        return nullptr;
       }
       if (PyDict_SetItem(ret.get(), k.get(), v.get()) == -1) {
-        return NULL;
+        return nullptr;
       }
     }
 
@@ -792,12 +792,12 @@
         ThriftModule = PyImport_ImportModule("thrift.Thrift");
       }
       if (!ThriftModule) {
-        return NULL;
+        return nullptr;
       }
 
       ScopedPyObject cls(PyObject_GetAttr(ThriftModule, INTERN_STRING(TFrozenDict)));
       if (!cls) {
-        return NULL;
+        return nullptr;
       }
 
       ScopedPyObject arg(PyTuple_New(1));
@@ -811,7 +811,7 @@
   case T_STRUCT: {
     StructTypeArgs parsedargs;
     if (!parse_struct_args(&parsedargs, typeargs)) {
-      return NULL;
+      return nullptr;
     }
     return readStruct(Py_None, parsedargs.klass, parsedargs.spec);
   }
@@ -823,7 +823,7 @@
   case T_U64:
   default:
     PyErr_Format(PyExc_TypeError, "Unexpected TType for decodeValue: %d", type);
-    return NULL;
+    return nullptr;
   }
 }
 
@@ -833,26 +833,26 @@
   bool immutable = output == Py_None;
   ScopedPyObject kwargs;
   if (spec_seq_len == -1) {
-    return NULL;
+    return nullptr;
   }
 
   if (immutable) {
     kwargs.reset(PyDict_New());
     if (!kwargs) {
       PyErr_SetString(PyExc_TypeError, "failed to prepare kwargument storage");
-      return NULL;
+      return nullptr;
     }
   }
 
   detail::ReadStructScope<Impl> scope = detail::readStructScope(this);
   if (!scope) {
-    return NULL;
+    return nullptr;
   }
   while (true) {
     TType type = T_STOP;
     int16_t tag;
     if (!impl()->readFieldBegin(type, tag)) {
-      return NULL;
+      return nullptr;
     }
     if (type == T_STOP) {
       break;
@@ -860,7 +860,7 @@
     if (tag < 0 || tag >= spec_seq_len) {
       if (!skip(type)) {
         PyErr_SetString(PyExc_TypeError, "Error while skipping unknown field");
-        return NULL;
+        return nullptr;
       }
       continue;
     }
@@ -869,38 +869,38 @@
     if (item_spec == Py_None) {
       if (!skip(type)) {
         PyErr_SetString(PyExc_TypeError, "Error while skipping unknown field");
-        return NULL;
+        return nullptr;
       }
       continue;
     }
     StructItemSpec parsedspec;
     if (!parse_struct_item_spec(&parsedspec, item_spec)) {
-      return NULL;
+      return nullptr;
     }
     if (parsedspec.type != type) {
       if (!skip(type)) {
         PyErr_Format(PyExc_TypeError, "struct field had wrong type: expected %d but got %d",
                      parsedspec.type, type);
-        return NULL;
+        return nullptr;
       }
       continue;
     }
 
     ScopedPyObject fieldval(decodeValue(parsedspec.type, parsedspec.typeargs));
     if (!fieldval) {
-      return NULL;
+      return nullptr;
     }
 
     if ((immutable && PyDict_SetItem(kwargs.get(), parsedspec.attrname, fieldval.get()) == -1)
         || (!immutable && PyObject_SetAttr(output, parsedspec.attrname, fieldval.get()) == -1)) {
-      return NULL;
+      return nullptr;
     }
   }
   if (immutable) {
     ScopedPyObject args(PyTuple_New(0));
     if (!args) {
       PyErr_SetString(PyExc_TypeError, "failed to prepare argument storage");
-      return NULL;
+      return nullptr;
     }
     return PyObject_Call(klass, args.get(), kwargs.get());
   }
diff --git a/lib/py/src/ext/types.cpp b/lib/py/src/ext/types.cpp
index 68443fb..e8d6939 100644
--- a/lib/py/src/ext/types.cpp
+++ b/lib/py/src/ext/types.cpp
@@ -24,7 +24,7 @@
 namespace thrift {
 namespace py {
 
-PyObject* ThriftModule = NULL;
+PyObject* ThriftModule = nullptr;
 
 #if PY_MAJOR_VERSION < 3
 char refill_signature[] = {'s', '#', 'i'};
diff --git a/lib/py/src/ext/types.h b/lib/py/src/ext/types.h
index 5cd8dda..9b45dd0 100644
--- a/lib/py/src/ext/types.h
+++ b/lib/py/src/ext/types.h
@@ -83,7 +83,7 @@
 // replace with unique_ptr when we're OK with C++11
 class ScopedPyObject {
 public:
-  ScopedPyObject() : obj_(NULL) {}
+  ScopedPyObject() : obj_(nullptr) {}
   explicit ScopedPyObject(PyObject* py_object) : obj_(py_object) {}
   ~ScopedPyObject() {
     if (obj_)
@@ -98,7 +98,7 @@
   }
   PyObject* release() throw() {
     PyObject* tmp = obj_;
-    obj_ = NULL;
+    obj_ = nullptr;
     return tmp;
   }
   void swap(ScopedPyObject& other) throw() {