Function get_leaky_singleton

src/bthread/singleton_on_bthread_once.h:52–57

// but also on bthread with hanging operation.
template <typename T>
inline T* get_leaky_singleton() {
    using LeakySingleton = GetLeakySingleton<T>;
    bthread_once(LeakySingleton::g_create_leaky_singleton_once,
                 LeakySingleton::create_leaky_singleton);
    return LeakySingleton::_instance;
}

} // namespace bthread