std::ranges::not_equal_to
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ranges::not_equal_to
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Defined in header
<functional>
struct not_equal_to;
(since C++20)
Function object for performing comparisons. Deduces the parameter types of the function call operator from the arguments (but not the return type).
Contents
[edit] Nested types
Nested type
Definition
is_transparent
unspecified
[edit] Member functions
operator()
(public member function)
std::ranges::not_equal_to::operator()
template< class T, class U >
constexpr bool operator()( T&& t, U&& u ) const;
constexpr bool operator()( T&& t, U&& u ) const;
Equivalent to return !ranges::equal_to {}(std::forward <T>(t), std::forward <U>(u));.
This overload participates in overload resolution only if std::equality_comparable_with <T, U> is satisfied.
[edit] Notes
Unlike std::not_equal_to , std::ranges::not_equal_to requires both == and != to be valid (via the equality_comparable_with constraint), and is entirely defined in terms of std::ranges::equal_to.
[edit] Example
This section is incomplete
Reason: no example
Reason: no example
[edit] Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 3530 | C++20 | syntactic checks were relaxed while comparing pointers | only semantic requirements are relaxed |