...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::signals2::keywords::group_type — A template keyword for signal_type.
// In header: <boost/signals2/signal_type.hpp> template<typename Group> class group_type : public unspecified-type { };
This class is a template keyword which may be used to pass the wrapped Group
template type to the signal_type metafunction as a named parameter.
The code for this class is generated by a calling a macro from the Boost.Parameter library:
BOOST_PARAMETER_TEMPLATE_KEYWORD(group_type)