< cpp‎ | memory
Defined in header <memory>
struct allocator_arg_t {};
(since C++11)

std::allocator_arg_t is an empty class type used to disambiguate the overloads of constructors and member functions of allocator-aware objects, including std::tuple, std::function, std::promise, and std::packaged_task.

[edit] See also

an object of type std::allocator_arg_t used to select allocator-aware constructors
checks if the specified type supports uses-allocator construction
(class template)