Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is an older version of Boost and was released in 2024. The current version is 1.89.0.

cancel_after_timer::timer_

basic_waitable_timer< Clock, WaitTraits, Executor > & timer_;