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 get_small_vector_opt

boost::container::dtl::get_small_vector_opt

// In header: <boost/container/small_vector.hpp>

template<typename Options> 
struct get_small_vector_opt {
  // types
  typedef Options type;
};