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

buffered_write_stream::async_flush

Start an asynchronous flush.

template<
    typename WriteHandler = default_completion_token_t<executor_type>>
DEDUCED async_flush(
    WriteHandler && handler = default_completion_token_t< executor_type >());

Completion Signature

void(boost::system::error_code, std::size_t)