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