How do I generate thread-safe uniform random numbers?

Question

My program needs to generate many random integers in some range (int min, int max). Each call will have a different range. What is a good (preferably thread-safe) w

Answer 1

I am a person from the future with the same problem. The accepted answer won't compile on MSVC 2013, because it doesn't implement thread_local (and using __declspec(thread) doesn't work because it doesn't like constructors).

The memory leak in your solution can be moved off the heap by modifying everything to use placement new.

Here's my solution (combined from a header and source file):

#ifndef BUILD_COMPILER_MSVC
thread_local std::mt19937 _generator;
#else
__declspec(thread) char _generator_backing[sizeof(std::mt19937)];
__declspec(thread) std::mt19937* _generator;
#endif
template  inline type_float get_uniform(void) {
    std::uniform_real_distribution distribution;
    #ifdef BUILD_COMPILER_MSVC
        static __declspec(thread) bool inited = false;
        if (!inited) {
            _generator = new(_generator_backing) std::mt19937();
            inited = true;
        }
        return distribution(*_generator);
    #else
        return distribution(_generator);
    #endif
}