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polymorphic_allocator()noexcept; (1) polymorphic_allocator(constpolymorphic_allocator&other)=default; (2) template<classU>polymorphic_allocator(constpolymorphic_allocator<U>&other)noexcept; (3) polymorphic_allocator(std::pmr::memory_resource*r); (4) Constructs a new polymorphic_allocator.
1) Constructs a polymorphic_allocator using the return value of std::pmr::get_default_resource() as the underlying memory resource.
2,3) Constructs a polymorphic_allocator using other.resource() as the underlying memory resource.
4) Constructs a polymorphic_allocator using r as the underlying memory resource. This constructor provides an implicit conversion from std::pmr::memory_resource*.
Parameters
other - another polymorphic_allocator to copy from r - pointer to the memory resource to use. May not be null Exceptions
4) Throws nothing.
Notes
Copying a container using a polymorphic_allocator will not call the allocator's copy constructor. Instead, the new container will use the return value of
select_on_container_copy_construction
(a default-constructed polymorphic_allocator) as its allocator.
See also