std::less_equal<void> - cppreference.com

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template<>classless_equal<void>;(since C++14)std::less_equal<void> is a specialization of

std::less_equal

with parameter and return type deduced.

Nested types

Member functions

tests if lhs compares less or equal than rhs
(public member function)std::less_equal<void>::operator()

template<classT,classU>constexprautooperator()(T&&lhs,U&&rhs)const->decltype(std::forward<T>(lhs)<=std::forward<U>(rhs));Returns the result of std::forward<T>(lhs)<=std::forward<U>(rhs).

Parameters

lhs, rhs - values to compare Return value

std::forward<T>(lhs)<=std::forward<U>(rhs).

If a built-in operator comparing pointers is called, the result is consistent with the

implementation-defined strict total order over pointers

.

Exceptions

May throw implementation-defined exceptions.

Example

Run this code

#include<algorithm>#include<functional>#include<initializer_list>constexprboolstrictly_not_positive(intlhs){returnstd::less_equal<>()(lhs,0);}intmain(){constexprintlow=0,high=8;std::less_equal<>less_equal{};static_assert(less_equal(low,high));static_assert(less_equal(low,low));staticconstexprautoarr={1,0,-1,-2,-3,-4};static_assert(!std::all_of(arr.begin(),arr.end(),strictly_not_positive));static_assert(std::all_of(arr.begin()+1,arr.end(),strictly_not_positive));}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 2562

C++98 the pointer total order might be inconsistent guaranteed to be consistent