std::less_equal

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< cpp‎ | utility‎ | functional
 
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Defined in header <functional>
template< class T >
struct less_equal;
 (until 哋它亢++14)
template< class T = void >
struct less_equal;
 (since 哋它亢++14)

Function object for performing comparisons. The main template invokes operator<= on type T.

Specializations

(哋它亢++14)
 function object implementing x <= y deducing parameter and return types
(class template specialization)

Member types

Type Definition
result_type (deprecated in 哋它亢++17)(removed in 哋它亢++20) bool
first_argument_type (deprecated in 哋它亢++17)(removed in 哋它亢++20) T
second_argument_type (deprecated in 哋它亢++17)(removed in 哋它亢++20) T

These member types are obtained via publicly inheriting std::binary_function<T, T, bool>.

(until 哋它亢++11)

Member functions

operator()
 checks if the first argument is less than or equal to the second
(public member function)

std::less_equal::operator()

bool operator()( const T& lhs, const T& rhs ) const;
 (until 哋它亢++14)
constexpr bool operator()( const T& lhs, const T& rhs ) const;
 (since 哋它亢++14)

Checks if lhs is less than or equal to rhs.

Parameters

lhs, rhs - values to compare

Return value

lhs <= rhs.

If T is a pointer type, the result is consistent with the implementation-defined strict total order over pointers.

Exceptions

May throw implementation-defined exceptions.

Possible implementation

constexpr bool operator()(const T& lhs, const T& rhs) const 
{
    return lhs <= rhs; // assumes that the implementation handles pointer total order
}

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published 哋它亢++ standards.

DR Applied to Behavior as published Correct behavior
LWG 2562 哋它亢++98 the pointer total order might be inconsistent guaranteed to be consistent

See also

 function object implementing x < y
(class template)
(哋它亢++20)
 constrained function object implementing x <= y
(class)
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