20 Memory management library [mem]

20.4 Memory resources [mem.res]

20.4.3 Class template polymorphic_­allocator [mem.poly.allocator.class]

20.4.3.2 Constructors [mem.poly.allocator.ctor]

polymorphic_allocator() noexcept;
Effects: Sets memory_­rsrc to get_­default_­resource().
polymorphic_allocator(memory_resource* r);
Preconditions: r is non-null.
Effects: Sets memory_­rsrc to r.
Throws: Nothing.
[Note 1:
This constructor provides an implicit conversion from memory_­resource*.
— end note]
template<class U> polymorphic_allocator(const polymorphic_allocator<U>& other) noexcept;
Effects: Sets memory_­rsrc to other.resource().