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

C++

Language

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Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

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Algorithms library

Iterators library

Numerics library

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Localizations library

Regular expressions library (C++11)

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Technical Specifications

Utilities library

Type support (basic types, RTTI, type traits)
Dynamic memory management
Error handling
Program utilities
Variadic functions
Library feature-test macros
Date and time
Function objects
initializer_list (C++11)
bitset
hash (C++11)
integer_sequence (C++14)
Relational operators (deprecated)
rel_ops::operator!=rel_ops::operator>rel_ops::operator<=rel_ops::operator>=
Comparisons (C++20)
strong_order weak_order partial_order strong_equal weak_equal	strong_ordering weak_ordering partial_ordering strong_equality weak_equality	is_eqis_neqis_ltis_lteqis_gtis_gteq
common_comparison_category
Common vocabulary types
pair tuple (C++11) apply (C++17) make_from_tuple (C++17)	optional (C++17) any (C++17) variant (C++17)
Swap, forward and move
swap
exchange (C++14)
forward (C++11)
move (C++11)
move_if_noexcept (C++11)
Elementary string conversions
to_chars (C++17)
from_chars (C++17)
chars_format (C++17)
Type operations
declval (C++11)
as_const (C++17)

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

See also

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