std::pmr:: operator==, std::pmr:: operator!=

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std::pmr::polymorphic_allocator
Defined in header <memory_resource>
template < class T1, class T2 >

bool operator == ( const std:: pmr :: polymorphic_allocator < T1 > & lhs,

const std:: pmr :: polymorphic_allocator < T2 > & rhs ) noexcept ;
(1) (since C++17)
friend bool operator == ( const polymorphic_allocator & lhs,
const polymorphic_allocator & rhs ) noexcept ;
(2) (since C++17)
template < class T1, class T2 >

bool operator ! = ( const std:: pmr :: polymorphic_allocator < T1 > & lhs,

const std:: pmr :: polymorphic_allocator < T2 > & rhs ) noexcept ;
(3) (since C++17)
(until C++20)
friend bool operator ! = ( const polymorphic_allocator & lhs,
const polymorphic_allocator & rhs ) noexcept ;
(4) (since C++17)
(until C++20)

Compares two polymorphic allocators. Two polymorphic allocators compare equal if their underlying memory resource compares equal.

1) Returns * lhs. resource ( ) == * rhs. resource ( ) .
2) Same as (1) , allowing conversion to polymorphic_allocator .
This function is not visible to ordinary unqualified or qualified lookup , and can only be found by argument-dependent lookup when std::pmr::polymorphic_allocator is an associated class of the arguments.
3) Returns ! ( lhs == rhs ) .
4) Same as (3) , allowing conversion to polymorphic_allocator .
This function is not visible to ordinary unqualified or qualified lookup , and can only be found by argument-dependent lookup when std::pmr::polymorphic_allocator is an associated class of the arguments.

The != operator is synthesized from operator== .

(since C++20)

Parameters

lhs, rhs - polymorphic allocators to compare

Return value

1,2) * lhs. resource ( ) == * rhs. resource ( )
3,4) ! ( lhs == rhs )

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 3683 C++17 polymorphic_allocator could not be compared with types convertible to it overload added
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