std::future::operator=
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                    | future& operator=( future&& other ); | (1) | (since C++11) | 
| future& operator=( const future& other ) = delete; | (2) | (since C++11) | 
Assigns the contents of another future object.
1) Releases any shared state and move-assigns the contents of other to *this. After the assignment, other.valid() == false and this->valid() will yield the same value as other.valid() before the assignment.
2) std::future is not CopyAssignable.
[edit] Parameters
| other | - | a std::futurethat will transfer state to *this | 
[edit] Return value
*this
[edit] Exceptions
noexcept specification:  
noexcept
  

