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std::is_eq, std::is_neq, std::is_lt, std::is_gt, std::is_lteq, std::is_gteq

Defined in header <compare> 
constexpr bool is_eq(std::weak_equality cmp) noexcept;
 (1) (since C++20) 
constexpr bool is_neq(std::weak_equality cmp) noexcept;
 (2) (since C++20) 
constexpr bool is_lt(std::partial_ordering cmp) noexcept;
 (3) (since C++20) 
constexpr bool is_lteq(std::partial_ordering cmp) noexcept;
 (4) (since C++20) 
constexpr bool is_gt(std::partial_ordering cmp) noexcept;
 (5) (since C++20) 
constexpr bool is_gteq(std::partial_ordering cmp) noexcept
 (6) (since C++20)

These functions take a result of 3-way comparison and convert it to the result of one of the six relational operators.

Specifically, these functions return.

1) cmp == 0
2) cmp != 0
3) cmp < 0
4) cmp <= 0
5) cmp > 0
6) cmp >= 0

Parameters

cmp - result of 3-way comparison

Return value

bool result of the corresponding relational operation.

Example

See also

(C++20)
 the result type of 3-way comparison that supports all 6 operators, is not substitutable, and allows incomparable values
(class)
(C++20)
 the result type of 3-way comparison that supports only equality/inequality and is not substitutable
(class)

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