std::promise<R>::swap
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                    |   void swap( promise& other ) noexcept;  | 
(since C++11) | |
Exchanges the shared states of two promise objects.
Parameters
| other | - | the promise to swap with | 
Return value
(none)
Example
| This section is incomplete Reason: no example  | 
See also
|    (C++11)  | 
  specializes the std::swap algorithm  (function template)  |