is_equality_comparable

Header

#include <tick/traits/is_equality_comparable.h>

Description

Checks if type T has operator == and != and is convertible to bool.

Requirements

The type T satisfies is_equality_comparable if

Given:

• a, and b expressions of type T or const T

The following expressions must be valid:

Expression	Return type
a == b	implicitly convertible to bool
a != b	implicitly convertible to bool

Synopsis

TICK_TRAIT(is_equality_comparable)
{
    template<class T>
    auto require(T&& x) -> valid<
        decltype(returns<bool>(x == x)),
        decltype(returns<bool>(x != x))
    >;

    template<class T, class U>
    auto require(T&& x, U&& y) -> valid<
        decltype(require(std::forward<T>(x))),
        decltype(require(std::forward<U>(y))),
        decltype(returns<bool>(x == y)),
        decltype(returns<bool>(x != y)),
        decltype(returns<bool>(y == x)),
        decltype(returns<bool>(y != x))
    >;
};