...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Construct an async result from a given handler.
async_result( Handler & );
When using a specalised async_result
,
the constructor has an opportunity to initialise some state associated
with the handler, which is then returned from the initiating function.