Compiler error on <mutex>:304 by Jorge.Ferreira

A compiler error:

1>c:\program files\microsoft visual studio 11.0\vc\include\mutex(304): error C4716: 'std::unique_lock<std::mutex>::try_lock' : must return a value

occurs when compiling the following program:

#include "stdafx.h"
#include <mutex>

std::mutex m;

int _tmain(int argc, _TCHAR* argv[])
{
    std::unique_lock<std::mutex> lock_a(m, std::defer_lock);
    lock_a.try_lock();
    return 0;
}

The try_lock method of std::unique_lock must return a value. A possible fix would be:

bool try_lock() _NOEXCEPT
{    // try to lock the mutex
    _Owns = _Pmtx->try_lock();
    return (_Owns);
}