Difference between revisions of "cpp/memory/polymorphic allocator/operator eq"
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< cpp | memory | polymorphic allocator
Andreas Krug (Talk | contribs) m (.) |
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===Return value=== | ===Return value=== | ||
| − | @1 | + | @1,2@ {{c|1=*lhs.resource() == *rhs.resource()}} |
| − | @3 | + | @3,4@ {{c|1=!(lhs == rhs)}} |
===Defect reports=== | ===Defect reports=== | ||
Latest revision as of 23:22, 6 October 2023
| Defined in header <memory_resource>
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||
| template< class T1, class T2 > bool operator==( const std::pmr::polymorphic_allocator<T1>& lhs, |
(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, |
(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
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.
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
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.
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 |
(since C++20) |
[edit] Parameters
| lhs, rhs | - | polymorphic allocators to compare |
[edit] Return value
1,2) *lhs.resource() == *rhs.resource()
3,4) !(lhs == rhs)
[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 3683 | C++17 | polymorphic_allocator could not be compared with types convertible to it
|
overload added |
