Method allocator_ref

test/mock-allocator.h:54–54

      fmt::bool_constant<PropagateOnMove>;

  explicit allocator_ref(Allocator* alloc = nullptr) : alloc_(alloc) {}

  allocator_ref(const allocator_ref& other) : alloc_(other.alloc_) {}
  allocator_ref(allocator_ref&& other) { move(other); }