#include <istream>
#include <ostream>
#include <boost/optional/optional.hpp>
namespace boost {
template <class CharType, class CharTrait, class T>
std::basic_ostream<CharType, CharTrait>&
operator<<(std::basic_ostream<CharType, CharTrait>& out, optional<T> const& v);
template <class CharType, class CharTrait>
std::basic_ostream<CharType, CharTrait>&
operator<<(std::basic_ostream<CharType, CharTrait>& out, none_t const&);
template<class CharType, class CharTrait, class T>
std::basic_istream<CharType, CharTrait>&
operator>>(std::basic_istream<CharType, CharTrait>& in, optional<T>& v);
}