std::experimental::future<T>::operator=
Min standard notice:
Assigns the contents of another future object.
# Declarations
std::experimental::future<T>& operator=( std::experimental::future<T>&& other ) noexcept;
std::experimental::future<T>& operator=( const std::experimental::future<T>& other ) = delete;
# Parameters
other: a std::experimental::future that will transfer state to *this
# Return value
*this