#include <iosfwd>
namespace std {
using streamoff = implementation-defined;
using streamsize = implementation-defined;
template<class stateT> class fpos;
class ios_base;
template<class charT, class traits = char_traits<charT>>
class basic_ios;
ios_base& boolalpha (ios_base& str);
ios_base& noboolalpha(ios_base& str);
ios_base& showbase (ios_base& str);
ios_base& noshowbase (ios_base& str);
ios_base& showpoint (ios_base& str);
ios_base& noshowpoint(ios_base& str);
ios_base& showpos (ios_base& str);
ios_base& noshowpos (ios_base& str);
ios_base& skipws (ios_base& str);
ios_base& noskipws (ios_base& str);
ios_base& uppercase (ios_base& str);
ios_base& nouppercase(ios_base& str);
ios_base& unitbuf (ios_base& str);
ios_base& nounitbuf (ios_base& str);
ios_base& internal (ios_base& str);
ios_base& left (ios_base& str);
ios_base& right (ios_base& str);
ios_base& dec (ios_base& str);
ios_base& hex (ios_base& str);
ios_base& oct (ios_base& str);
ios_base& fixed (ios_base& str);
ios_base& scientific (ios_base& str);
ios_base& hexfloat (ios_base& str);
ios_base& defaultfloat(ios_base& str);
enum class io_errc {
stream = 1
};
template<> struct is_error_code_enum<io_errc> : public true_type { };
error_code make_error_code(io_errc e) noexcept;
error_condition make_error_condition(io_errc e) noexcept;
const error_category& iostream_category() noexcept;
}