23 General utilities library [utilities]

23.14 Function objects [function.objects]

23.14.7 Comparisons [comparisons]

23.14.7.4 Class template less [comparisons.less]

template <class T = void> struct less { constexpr bool operator()(const T& x, const T& y) const; }; constexpr bool operator()(const T& x, const T& y) const;
Returns: x < y.
template <> struct less<void> { template <class T, class U> constexpr auto operator()(T&& t, U&& u) const -> decltype(std::forward<T>(t) < std::forward<U>(u)); using is_transparent = unspecified; }; template <class T, class U> constexpr auto operator()(T&& t, U&& u) const -> decltype(std::forward<T>(t) < std::forward<U>(u));
Returns: std​::​forward<T>(t) < std​::​forward<U>(u).