Prevent mixing debug and release libraries
//header:
class DLLIMPEXP Dummy
{
   static int x;
   virtual void dummy();
}
//cpp
#ifdef DEBUG
int Dummy::x = 0;
void Dummy::dummy()
{
}
#endif

#ifdef NDEBUG
  namespace project {
#else
  namespace project { namespace debug {
#endif

// content

#ifdef NDEBUG
  }
#else
  }
  using namespace debug;
  }
#endif

myLib.h  // Release Version
myLibd.h // Debug Version

#ifndef _DLL
// C runtime as dll
#  ifdef _DEBUG
#    pragma comment(lib, "MyLibD.lib")
#  else
#    pragma comment(lib, "MyLib.lib")
#  endif
#else
// C runtime statically
#  ifdef _DEBUG
#    pragma comment(lib, "MyLibSD.lib")
#  else
#    pragma comment(lib, "MyLibS.lib")
#  endif
#endif

#ifndef _DLL
// C runtime as dll
#  ifdef _DEBUG
#    pragma comment(lib, "debug/dynamic/MyLib.lib")
#  else
#    pragma comment(lib, "release/dynamic/MyLib.lib")
#  endif
#else
// C runtime statically
#  ifdef _DEBUG
#    pragma comment(lib, "debug/static/MyLib.lib")
#  else
#    pragma comment(lib, "debug/static/MyLib.lib")
#  endif
#endif