cpp/experimental/lib extensions/promise/promise

Constructs a object.

@1@ Default constructor. Constructs the promise with an empty shared state.

@2@ Constructs the promise with an empty shared state. The shared state is allocated using, which is treated as a type-erased allocator (see below).

@3@ Move constructor. Constructs the promise with the shared state of using move semantics. After construction, has no shared state.

@4@ is not copyable.

Exceptions
@1-2@ (none)