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
boost::xpressive::as — as() is a lazy funtion for lexically casting a parameter to a different type.
// In header: <boost/xpressive/regex_actions.hpp> template<typename T, typename A> unspecified as(A const & a);