Enabling additional compiler warnings

You certainly heard the recommendation to set your compiler warnings to the highest possible level, and you probably follow it. It is a good advice, but many users of MSVC++ are unaware of additional warnings, which are disabled by default even if you use warning level 4 (/W4). You can find the full list of disabled warnings in MSDN; here are the most useful ones:

#pragma warning(default:4619) // wrong warning number in pragma
#pragma warning(default:4061) // enum value was not handled in switch
#pragma warning(default:4263) // wrong parameters count in the overloaded function
#pragma warning(default:4265) // the class has a virtual function,
                              // but the destructor is non-virtual
#pragma warning(default:4287) // negative constant is assigned to unsigned variable
#pragma warning(default:4296) // an unsigned variable is compared with zero
#pragma warning(default:4555) // no operation
#pragma warning(default:4347) // template function is called instead of the function
                              // with the same name
#pragma warning(default:4545 4546 4547 4548 4549) // various errors with comma operator
#pragma warning(default:4557) // assume with side effects
#pragma warning(default:4710) // inline function was not inlined
#pragma warning(default:4836) // local or unnamed type is used as an template argument
#pragma warning(default:4905) // L"abc" was converted to CHAR*
#pragma warning(default:4906) // "abc" was converted to WCHAR*

Finally, double-check that you have set "warning level 4" in the project properties!