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

 

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Uninitialized memory algorithms uninitialized_copy uninitialized_fill uninitialized_move (C++17) uninitialized_default_construct (C++17) uninitialized_value_construct (C++17) destroy (C++17) destroy_at (C++17) voidify (C++20) uninitialized_copy_n (C++11) uninitialized_fill_n uninitialized_move_n (C++17) uninitialized_default_construct_n (C++17) uninitialized_value_construct_n (C++17) destroy_n (C++17) construct_at (C++20) Constrained uninitialized memory algorithms ranges::uninitialized_copy (C++20) ranges::uninitialized_fill (C++20) ranges::uninitialized_move (C++20) ranges::construct_at (C++20) ranges::destroy (C++20) ranges::destroy_n (C++20) ranges::destroy_at (C++20) ranges::uninitialized_copy_n (C++20) ranges::uninitialized_fill_n (C++20) ranges::uninitialized_move_n (C++20) ranges::uninitialized_default_construct (C++20) ranges::uninitialized_value_construct (C++20) ranges::uninitialized_default_construct_n (C++20)   ranges::uninitialized_value_construct_n (C++20) Allocators allocator allocator_traits (C++11) allocation_result (C++23) allocator_arg (C++11) uses_allocator (C++11) uses_allocator_construction_args (C++20) make_obj_using_allocator (C++20) uninitialized_construct_using_allocator (C++20) scoped_allocator_adaptor (C++11) pmr::polymorphic_allocator (C++17) Memory resources pmr::memory_resource (C++17) pmr::get_default_resource (C++17) pmr::set_default_resource (C++17) pmr::new_delete_resource (C++17) pmr::null_memory_resource (C++17) pmr::synchronized_pool_resource (C++17) pmr::unsynchronized_pool_resource (C++17)   pmr::monotonic_buffer_resource (C++17) pmr::pool_options (C++17) Garbage collection support declare_reachable (C++11)(until C++23) undeclare_reachable (C++11)(until C++23) declare_no_pointers (C++11)(until C++23) undeclare_no_pointers (C++11)(until C++23) pointer_safety (C++11)(until C++23) get_pointer_safety (C++11)(until C++23) Uninitialized storage raw_storage_iterator (until C++20*) get_temporary_buffer (until C++20*) return_temporary_buffer (until C++20*) Explicit lifetime management start_lifetime_asstart_lifetime_as_array (C++23)(C++23)

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std::pmr::polymorphic_allocator

Member functions

polymorphic_allocator::polymorphic_allocator

polymorphic_allocator::allocate

polymorphic_allocator::deallocate

polymorphic_allocator::construct

polymorphic_allocator::destroy (C++20/26*)

polymorphic_allocator::allocate_bytes (C++20)

polymorphic_allocator::deallocate_bytes (C++20)

polymorphic_allocator::allocate_object (C++20)

polymorphic_allocator::deallocate_object (C++20)

polymorphic_allocator::new_object (C++20)

polymorphic_allocator::delete_object (C++20)

polymorphic_allocator::select_on_container_copy_construction

polymorphic_allocator::resource

Non-member functions

operator==operator!= (until C++20)

 

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