std::uses_allocator<std::promise>_C++中文网
template< class R, class Alloc >
struct uses_allocator<std::promise<R>, Alloc> : std::true_type { };
std::uses_allocator<std::promise>_C++中文网
template< class R, class Alloc >
struct uses_allocator<std::promise<R>, Alloc> : std::true_type { };