= Uses-allocator Construction To support code bases which are already using polymorphic allocators, the containers in this library support {std_uses_allocator} construction. For <<ref_array>>, <<ref_object>>, <<ref_string>>, and <<ref_value>>:
Practically, this means that when a library container type is used in a standard container that uses a polymorphic allocator, the allocator will propagate to the JSON type. For example: