Sprout/sprout/variant/io.hpp
2012-10-24 20:52:09 +09:00

40 lines
1 KiB
C++

#ifndef SPROUT_VARIANT_IO_HPP
#define SPROUT_VARIANT_IO_HPP
#include <sprout/config.hpp>
#include <sprout/variant/variant.hpp>
#include <sprout/variant/static_visitor.hpp>
namespace sprout {
namespace detail {
template<typename OStream>
class variant_output_visitor
: public sprout::static_visitor<>
{
public:
typedef OStream ostream_type;
private:
ostream_type& out_;
public:
explicit variant_output_visitor(ostream_type& out)
: out_(out)
{}
template<typename T>
void operator()(T const& operand) const {
out_ << operand;
}
};
} // namespace detail
//
// operator<<
//
template<typename Elem, typename Traits, typename... Types>
inline std::basic_ostream<Elem, Traits>&
operator<<(std::basic_ostream<Elem, Traits>& lhs, sprout::variant<Types...> const& rhs) {
sprout::detail::variant_output_visitor<std::basic_ostream<Elem, Traits> > visitor(lhs);
rhs.apply_visitor(visitor);
return lhs;
}
} // namespace sprout
#endif // #ifndef SPROUT_VARIANT_IO_HPP