...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::xpressive::op::str::result<This(Sub)>
// In header: <boost/xpressive/regex_actions.hpp> template<typename This, typename Sub> struct result<This(Sub)> { // types typedef remove_reference< Sub >::type::string_type type; };