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

Struct template sig

boost::function::sig — Lambda library support

// In header: <boost/function.hpp>



// Lambda library support
template<typename Args> 
struct sig {
  // types
  typedef result_type type;
};