50 template<
typename LeftSig,
typename RightSig>
53 using Left_f = std::function<LeftSig>;
54 using Right_f = std::function<RightSig>;
72 template<
typename L,
typename R>
86 explicit operator bool ()
const
88 return Left_ && Right_;
104 template<
typename... Args>
105 auto Left (Args&&... args)
const
107 return Left_ (std::forward<Args> (args)...);
123 template<
typename... Args>
124 auto Right (Args&&... args)
const
126 return Right_ (std::forward<Args> (args)...);