C++ Concurrency in Action, Second Edition

std::shared_future::valid member function

Checks if an std::shared_future instance is associated with an asynchronous result.

• Declaration

  bool valid() const noexcept;

• Returns true if *this has an associated asynchronous result, false otherwise.

• Throws Nothing.

std::shared_future::wait member function

If the state associated with *this contains a deferred function, invokes the deferred function. Otherwise, waits until the asynchronous result associated with an instance of std::shared_future is ready.

• Declaration

  void wait() const;

• Preconditions this->valid() would return true.

• Effects Calls to get() and wait() from multiple threads on std::shared_future instances that share the same associated state are serialized. If ...