A cross platform concurrent queue header, including a simple implementation using Unix pipes when no existing implementation is present

concurrent_queue.h

#pragma once
#ifdef _MSC_VER

    #include <concurrent_queue.h>
    using concurrency::concurrent_queue;

#else
    #ifdef USE_INTEL_TBB
        #include <tbb/concurrent_queue.h>
        using tbb::concurrent_queue;
    #else

        #include <unistd.h>
        #include <cstdlib>

        template<typename T>
        class concurrent_queue {

            int FD[2];

            public:
            concurrent_queue(){
                pipe(FD);
            }

            ~concurrent_queue(){
                close(FD[0]);
                close(FD[1]);
            }

            void push(const T &aP){

                write(FD[1], &aP, sizeof(T));

            }

            bool try_pop(T &aTo){
                return (read(FD[0], &aTo, sizeof(T))>0);
            }

            bool pop_if_present(T &aTo){
                return try_pop(aTo);
            }

            size_t unsafe_size(){
                uint64_t lAt = lseek(FD[0], 0, SEEK_CUR);
                uint64_t rAt = lseek(FD[0], 0, SEEK_END);
                lseek(FD[0], lAt, SEEK_SET);

                return rAt;
            }

        };


    #endif

#endif