...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::front::result<This(Sequence)>
template<typename This, typename Sequence> struct result<This(Sequence)> { // types typedef mpl::if_< is_const< sequence_type >, typename sequence_type::const_reference, typename sequence_type::reference >::type type; // public member functions typedef UNREF(Sequence) ; };