if check lo-cflag -pthread; then
    lo_cflags="$lo_cflags -pthread"
fi

if check include pthread.h; then
    cfg:set 'working semaphores' "$(c++:compile "
        #include <semaphore.h>

        int main() {
            sem_t semaphore;
            return sem_init(&semaphore, 0, 0) == -1 ? $no : $yes;
        }
    ")"

    cfg:set 'cross-thread wait' "$(c++:compile "
        #include <sys/errno.h>
        #include <sys/types.h>
        #include <sys/wait.h>

        #include <pthread.h>
        #include <unistd.h>

        int child;

        extern \"C\"
        void *start(void *) {
            return waitpid(child, 0, 0) == -1 ? &child : 0;
        }

        int main() {
            void *status(0);

            if (child = fork()) {
                ::pthread_t thread;
                ::pthread_create(&thread, 0, &start, 0);
                ::pthread_join(thread, &status);
            }

            return status == 0 ? $yes : $no;
        }
    ")"
fi