...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Returns ownership of the handler associated with this object.
Handler release_handler();
This function is used to transfer ownership of the handler to the caller, by move-construction. After the move, the only valid operations on the base object are move construction and destruction.