Boost C++ Libraries of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards


Header <boost/optional/optional_fwd.hpp>

namespace boost {

template <class T> class optional ;

template <class T> void swap ( optional<T>& , optional<T>& );

template <class T> struct optional_swap_should_use_default_constructor ;

} // namespace boost

This header only contains declarations.