N3784+

future

namespace std {
	template< class T >
	class continuator;
		
	template< class T >
	class shared_continuator;

	template< class Type >
	continuator async_cast(std::future<Type> fut) noexcept;
	
	template< class Type >
	shared_continuator async_cast(std::shared_future<Type> fut) noexcept;
}