W3cubDocs

/C++

std::promise<R>::promise

promise();
 (1) (since C++11) 
template< class Alloc >
promise( std::allocator_arg_t, const Alloc& alloc );
 (2) (since C++11) 
promise( promise&& other ) noexcept;
 (3) (since C++11) 
promise( const promise& other ) = delete;
 (4) (since C++11)

Constructs a promise 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 alloc. Alloc must meet the requirements of Allocator.
3) Move constructor. Constructs the promise with the shared state of other using move semantics. After construction, other has no shared state.
4) promise is not copyable.

Parameters

alloc - allocator to use to allocate the shared state
other - another promise to acquire the state from

Exceptions

1-2) May throw implementation-defined exceptions.

Example

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/thread/promise/promise