std::shared_future<T>::valid
From cppreference.com
< cpp | thread | shared future
| bool valid() const noexcept; |
(since C++11) | |
Checks if the future refers to a shared state.
This is the case only for futures that were not default-constructed or moved from. Unlike std::future, std::shared_future's shared state is not invalidated when get() is called.
The behavior is undefined if any member function other than the destructor, the copy-assignment operator, the move-assignment operator, or valid is called on a shared_future that does not refer to shared state (although implementations are encouraged to throw std::future_error indicating no_state in this case). It is valid to move or copy from a shared_future object for which valid() is false
Parameters
(none)
Return value
true if *this refers to a shared state, otherwise false.
Example
| This section is incomplete Reason: no example |
See also
| waits for the result to become available (public member function) |