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 2018. The current version is 1.89.0.
Defined in header <boost/beast/websocket/stream.hpp>
template< class> class close_op
Convenience header <boost/beast/websocket.hpp>