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std::allocator_traits::select_on_container_copy_construction(3) C++ Standard Libary std::allocator_traits::select_on_container_copy_construction(3)

NAME

std::allocator_traits::select_on_container_copy_construction - std::allocator_traits::select_on_container_copy_construction

Synopsis


Defined in header <memory>
static Alloc select_on_container_copy_construction( const Alloc& a ); (since C++11)
(until C++20)
static constexpr Alloc select_on_container_copy_construction( const (since C++20)
Alloc& a );


If possible, obtains the copy-constructed version of the allocator a, by calling
a.select_on_container_copy_construction(). If the above is not possible (e.g. Alloc
does not have the member function select_on_container_copy_construction()), then
returns a, unmodified.


This function is called by the copy constructors of all standard library containers.
It allows the allocator used by the constructor's argument to become aware that the
container is being copied and modify state if necessary.

Parameters


a - allocator used by a standard container passed as an argument to a container copy
constructor

Return value


The allocator to use by the copy-constructed standard containers.

See also


copies the state of scoped_allocator_adaptor and all its select_on_container_copy_construction allocators
(public member function of
std::scoped_allocator_adaptor<OuterAlloc,InnerAlloc...>)

2022.07.31 http://cppreference.com