Added VS crtdbg memory leak tracking

include/flatbuffers/base.h

 #ifndef FLATBUFFERS_BASE_H_
 #define FLATBUFFERS_BASE_H_
 
+#if defined(_MSC_VER) && defined(_DEBUG)
+  #define _CRTDBG_MAP_ALLOC
+#endif
+
 #include <assert.h>
 
 #ifndef ARDUINO
 #include <cstdint>
 #endif
+
 #include <cstddef>
 #include <cstdlib>
 #include <cstring>
-#include <string>
+
+#if defined(_MSC_VER) && defined(_DEBUG)
+  #include <crtdbg.h>
+  #define DEBUG_NEW new(_NORMAL_BLOCK, __FILE__, __LINE__)
+  #define new DEBUG_NEW
+#endif
+
 #if defined(ARDUINO) && !defined(ARDUINOSTL_M_H)
-#include <utility.h>
+  #include <utility.h>
 #else
-#include <utility>
+  #include <utility>
 #endif
+
+#include <string>
 #include <type_traits>
 #include <vector>
 #include <set>
@@ -122,8 +135,8 @@
 #endif
 
 #if defined(_MSC_VER)
-#pragma warning(push)
-#pragma warning(disable: 4127) // C4127: conditional expression is constant
+  #pragma warning(push)
+  #pragma warning(disable: 4127) // C4127: conditional expression is constant
 #endif
 
 /// @endcond

tests/test.cpp

@@ -1541,6 +1541,8 @@ void UnionVectorTest() {
   fbb.Clear();
   fbb.Finish(Movie::Pack(fbb, movie_object));
 
+  delete movie_object;
+
   auto repacked_movie = GetMovie(fbb.GetBufferPointer());
 
   TestMovie(repacked_movie);
@@ -1737,15 +1739,22 @@ void TypeAliasesTest()
 }
 
 int main(int /*argc*/, const char * /*argv*/[]) {
+  #if defined(_MSC_VER) && defined(_DEBUG)
+    _CrtSetDbgFlag(_CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF
+      // For more thorough checking:
+      //| _CRTDBG_CHECK_ALWAYS_DF | _CRTDBG_DELAY_FREE_MEM_DF
+    );
+  #endif
+
   // Run our various test suites:
 
   std::string rawbuf;
   auto flatbuf1 = CreateFlatBufferTest(rawbuf);
-#if !defined(FLATBUFFERS_CPP98_STL)
+  #if !defined(FLATBUFFERS_CPP98_STL)
     auto flatbuf = std::move(flatbuf1);  // Test move assignment.
-#else
+  #else
     auto &flatbuf = flatbuf1;
-#endif // !defined(FLATBUFFERS_CPP98_STL)
+  #endif // !defined(FLATBUFFERS_CPP98_STL)
   AccessFlatBufferTest(reinterpret_cast<const uint8_t *>(rawbuf.c_str()),
                        rawbuf.length());
   AccessFlatBufferTest(flatbuf.data(), flatbuf.size());