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std::ranges::greater(3) C++ Standard Libary std::ranges::greater(3)

NAME

std::ranges::greater - std::ranges::greater

Synopsis


Defined in header <functional>
struct greater; (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).


Implementation-defined strict total order over pointers


The function call operator yields the implementation-defined strict total order over
pointers if the < operator between arguments invokes a built-in comparison operator
for a pointer, even if the built-in < operator does not.


The implementation-defined strict total order is consistent with the partial order
imposed by built-in comparison operators (<=>, <, >, <=, and >=), and consistent
among following standard function objects:


* std::less, std::greater, std::less_equal, and std::greater_equal, when the
template argument is a pointer type or void


* std::ranges::equal_to, std::ranges::not_equal_to, std::ranges::less,
std::ranges::greater, std::ranges::less_equal, std::ranges::greater_equal, and
std::compare_three_way

Member types


Member type Definition
is_transparent /* unspecified */

Member functions


operator() checks if the first argument is greater than the second
(public member function)

std::ranges::greater::operator()


template< class T, class U >


requires std::totally_ordered_with<T, U> // with different semantic requirements


constexpr bool operator()(T&& t, U&& u) const;


Compares t and u. Equivalent to return ranges::less{}(std::forward<U>(u),
std::forward<T>(t));.

Notes


Unlike std::greater, std::ranges::greater requires all six comparison operators <,
<=, >, >=, == and != to be valid (via the totally_ordered_with constraint) and is
entirely defined in terms of std::ranges::less.

Example


This section is incomplete
Reason: no example


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 only semantic requirements
comparing pointers relaxed

See also


greater function object implementing x > y
(class template)

2022.07.31 http://cppreference.com