C / C++ / MFC

#define _POSIX_THREADS

class CSemaphoreLock
{
public:
    CSemaphoreLock(HANDLE hSem) : m_hSem(hSem) { ::WaitForSingleObject(hSem, INFINITE); }
    ~CSemaphoreLock() { ::ReleaseSemaphore(m_hSem, 1, NULL); }

private:
    const HANDLE m_hSem;
};

#ifdef _MT
#  define SEMAPHORE_LOCK(HSEM) CSemaphoreLock TempLock_(HSEM)
#else
#  define SEMAPHORE_LOCK(HSEM)
#endif // _MT

 /MT Defines _MT so that multithread-specific versions of the run-time routines are selected from the standard header (.h) files. This option also causes the compiler to place the library name LIBCMT.lib into the .obj file so that the linker will use LIBCMT.lib to resolve external symbols. Either /MT or /MD (or their debug equivalents /MTd or /MDd) is required to create multithreaded programs.  <br />
/MTd Defines _DEBUG and _MT. Defining _MT causes multithread-specific versions of the run-time routines to be selected from the standard .h files. This option also causes the compiler to place the library name LIBCMTD.lib into the .obj file so that the linker will use LIBCMTD.lib to resolve external symbols. Either /MTd or /MDd (or their non-debug equivalents /MT or MD) is required to create multithreaded programs.  

<font color=blue>class</font> CBaseClass {
  <font color=blue>public</font>:
    <font color=blue>void</font> print() {
        printf(<font color=gray>"CBaseClass\n"</font>);
    }
};
 
<font color=blue>class</font> A : <font color=blue>public</font> CBaseClass {
  <font color=blue>public</font>:
    <font color=blue>void</font> print() {
        printf(<font color=gray>"A\n"</font>);
    }
};

CBaseClass* p = <font color=blue>new</font> A();
p->print();

<font color=blue>virtual void</font> print() { <font color=green>/*...*/</font> }

"One must learn from the bite of the fire to leave it alone." - Native American Proverb