diff --git a/lib/cpp/test/concurrency/Tests.cpp b/lib/cpp/test/concurrency/Tests.cpp
index 019ae67..f2b0111 100644
--- a/lib/cpp/test/concurrency/Tests.cpp
+++ b/lib/cpp/test/concurrency/Tests.cpp
@@ -41,7 +41,7 @@
     args[ix - 1] = std::string(argv[ix]);
   }
 
-  if (getenv("VALGRIND") != 0) {
+  if (getenv("VALGRIND") != nullptr) {
 	  // lower the scale of every test
 	  WEIGHT = 1;
   }
diff --git a/lib/cpp/test/concurrency/ThreadFactoryTests.h b/lib/cpp/test/concurrency/ThreadFactoryTests.h
index ad1613b..febe3f8 100644
--- a/lib/cpp/test/concurrency/ThreadFactoryTests.h
+++ b/lib/cpp/test/concurrency/ThreadFactoryTests.h
@@ -51,7 +51,7 @@
   public:
     ReapNTask(Monitor& monitor, int& activeCount) : _monitor(monitor), _count(activeCount) {}
 
-    void run() {
+    void run() override {
       Synchronized s(_monitor);
       
       if (--_count == 0) {
@@ -122,7 +122,7 @@
 
     SynchStartTask(Monitor& monitor, volatile STATE& state) : _monitor(monitor), _state(state) {}
 
-    void run() {
+    void run() override {
       {
         Synchronized s(_monitor);
         if (_state == SynchStartTask::STARTING) {
@@ -247,14 +247,14 @@
   class FloodTask : public Runnable {
   public:
     FloodTask(const size_t id, Monitor& mon) : _id(id), _mon(mon) {}
-    ~FloodTask() {
+    ~FloodTask() override {
       if (_id % 10000 == 0) {
 		Synchronized sync(_mon);
         std::cout << "\t\tthread " << _id << " done" << std::endl;
       }
     }
 
-    void run() {
+    void run() override {
       if (_id % 10000 == 0) {
 		Synchronized sync(_mon);
         std::cout << "\t\tthread " << _id << " started" << std::endl;
diff --git a/lib/cpp/test/concurrency/ThreadManagerTests.h b/lib/cpp/test/concurrency/ThreadManagerTests.h
index e9ed756..fee7c7c 100644
--- a/lib/cpp/test/concurrency/ThreadManagerTests.h
+++ b/lib/cpp/test/concurrency/ThreadManagerTests.h
@@ -63,7 +63,7 @@
     Task(Monitor& monitor, size_t& count, int64_t timeout)
       : _monitor(monitor), _count(count), _timeout(timeout), _startTime(0), _endTime(0), _done(false) {}
 
-    void run() {
+    void run() override {
 
       _startTime = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::steady_clock::now().time_since_epoch()).count();
 
@@ -124,7 +124,7 @@
 
     int64_t time00 = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::steady_clock::now().time_since_epoch()).count();
 
-    for (std::set<shared_ptr<ThreadManagerTests::Task> >::iterator ix = tasks.begin();
+    for (auto ix = tasks.begin();
          ix != tasks.end();
          ix++) {
 
@@ -151,7 +151,7 @@
     int64_t minTime = 9223372036854775807LL;
     int64_t maxTime = 0;
 
-    for (std::set<shared_ptr<ThreadManagerTests::Task> >::iterator ix = tasks.begin();
+    for (auto ix = tasks.begin();
          ix != tasks.end();
          ix++) {
 
@@ -201,7 +201,7 @@
     BlockTask(Monitor& entryMonitor, Monitor& blockMonitor, bool& blocked, Monitor& doneMonitor, size_t& count)
       : _entryMonitor(entryMonitor), _entered(false), _blockMonitor(blockMonitor), _blocked(blocked), _doneMonitor(doneMonitor), _count(count) {}
 
-    void run() {
+    void run() override {
       {
         Synchronized s(_entryMonitor);
         _entered = true;
@@ -275,7 +275,7 @@
             new ThreadManagerTests::BlockTask(entryMonitor, blockMonitor, blocked[1], doneMonitor, activeCounts[1])));
       }
 
-      for (std::vector<shared_ptr<ThreadManagerTests::BlockTask> >::iterator ix = tasks.begin();
+      for (auto ix = tasks.begin();
            ix != tasks.end();
            ix++) {
         threadManager->add(*ix);
diff --git a/lib/cpp/test/concurrency/TimerManagerTests.h b/lib/cpp/test/concurrency/TimerManagerTests.h
index a922826..313572a 100644
--- a/lib/cpp/test/concurrency/TimerManagerTests.h
+++ b/lib/cpp/test/concurrency/TimerManagerTests.h
@@ -44,9 +44,9 @@
         _success(false),
         _done(false) {}
 
-    ~Task() { std::cerr << this << std::endl; }
+    ~Task() override { std::cerr << this << std::endl; }
 
-    void run() {
+    void run() override {
 
       _endTime = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::steady_clock::now().time_since_epoch()).count();
       _success = (_endTime - _startTime) >= _timeout;
@@ -215,7 +215,7 @@
     // Verify behavior when removing the removed task
     try {
       timerManager.remove(timer);
-      assert(0 == "ERROR: This remove should send a NoSuchTaskException exception.");
+      assert(nullptr == "ERROR: This remove should send a NoSuchTaskException exception.");
     } catch (NoSuchTaskException&) {
     }
 
@@ -244,7 +244,7 @@
     // Verify behavior when removing the expired task
     try {
       timerManager.remove(timer);
-      assert(0 == "ERROR: This remove should send a NoSuchTaskException exception.");
+      assert(nullptr == "ERROR: This remove should send a NoSuchTaskException exception.");
     } catch (NoSuchTaskException&) {
     }