22 General utilities library [utilities]

22.10 Function objects [function.objects]

22.10.8 Comparisons [comparisons]

22.10.8.3 Class template not_equal_to [comparisons.not.equal.to]

template<class T = void> struct not_equal_to { 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 not_equal_to<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).