...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::top — top
is a PolymorphicFunctionObject for fetching the top element of a stack.
// In header: <boost/xpressive/regex_actions.hpp> struct top { // member classes/structs/unions template<typename Sig> struct result { }; template<typename This, typename Sequence> struct result<This(Sequence)> { // types typedef remove_reference< Sequence >::type sequence_type; typedef mpl::if_c< is_const< sequence_type >::value, typenamesequence_type::value_typeconst &, typenamesequence_type::value_type & >::type type; }; // public member functions template<typename Sequence> result< top(Sequence &)>::type operator()(Sequence &) const; };