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

Constructor.

template<
    class... BodyArgs>
message(
    header_type const& h,
    BodyArgs&&... body_args);

Name	Description
`h`	The header to copy construct from.
`body_args`	Optional arguments forwarded to the `body` constructor.