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
Defined in header <boost/static_string/static_string.hpp>
template<std::size_tN,std::size_tM, typename CharT, typename Traits> constexpr void swap(basic_static_string< N, CharT, Traits >& lhs,basic_static_string< M, CharT, Traits >& rhs);
Convenience header <boost/static_string.hpp>