Standard library header <ios>

#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;
 
 // manipulators
 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);
 
 // adjustfield
 ios_base& internal (ios_base& str);
 ios_base& left (ios_base& str);
 ios_base& right (ios_base& str);
 
 // basefield
 ios_base& dec (ios_base& str);
 ios_base& hex (ios_base& str);
 ios_base& oct (ios_base& str);
 
 // floatfield
 ios_base& fixed (ios_base& str);
 ios_base& scientific (ios_base& str);
 ios_base& hexfloat (ios_base& str);
 ios_base& defaultfloat(ios_base& str);
 
 // error reporting
 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;
}

namespace std {
 class ios_base {
 public:
 class failure; // see description
 
 // fmtflags
 using fmtflags = /*bitmask-type-1*/;
 static constexpr fmtflags boolalpha = /* unspecified */;
 static constexpr fmtflags dec = /* unspecified */;
 static constexpr fmtflags fixed = /* unspecified */;
 static constexpr fmtflags hex = /* unspecified */;
 static constexpr fmtflags internal = /* unspecified */;
 static constexpr fmtflags left = /* unspecified */;
 static constexpr fmtflags oct = /* unspecified */;
 static constexpr fmtflags right = /* unspecified */;
 static constexpr fmtflags scientific = /* unspecified */;
 static constexpr fmtflags showbase = /* unspecified */;
 static constexpr fmtflags showpoint = /* unspecified */;
 static constexpr fmtflags showpos = /* unspecified */;
 static constexpr fmtflags skipws = /* unspecified */;
 static constexpr fmtflags unitbuf = /* unspecified */;
 static constexpr fmtflags uppercase = /* unspecified */;
 static constexpr fmtflags adjustfield = /* see description */;
 static constexpr fmtflags basefield = /* see description */;
 static constexpr fmtflags floatfield = /* see description */;
 
 // iostate
 using iostate = /*bitmask-type-2*/;
 static constexpr iostate badbit = /* unspecified */;
 static constexpr iostate eofbit = /* unspecified */;
 static constexpr iostate failbit = /* unspecified */;
 static constexpr iostate goodbit = /* see description */;
 
 // openmode
 using openmode = /*bitmask-type-3*/;
 static constexpr openmode app = /* unspecified */;
 static constexpr openmode ate = /* unspecified */;
 static constexpr openmode binary = /* unspecified */;
 static constexpr openmode in = /* unspecified */;
 static constexpr openmode out = /* unspecified */;
 static constexpr openmode trunc = /* unspecified */;
 static constexpr openmode noreplace = /* unspecified */
 
 // seekdir
 using seekdir = /*bitmask-type-4*/;
 static constexpr seekdir beg = /* unspecified */;
 static constexpr seekdir cur = /* unspecified */;
 static constexpr seekdir end = /* unspecified */;
 
 class Init;
 
 // fmtflags state
 fmtflags flags() const;
 fmtflags flags(fmtflags fmtfl);
 fmtflags setf(fmtflags fmtfl);
 fmtflags setf(fmtflags fmtfl, fmtflags mask);
 void unsetf(fmtflags mask);
 
 streamsize precision() const;
 streamsize precision(streamsize prec);
 streamsize width() const;
 streamsize width(streamsize wide);
 
 // locales
 locale imbue(const locale& loc);
 locale getloc() const;
 
 // storage
 static int xalloc();
 long& iword(int idx);
 void*& pword(int idx);
 
 // destructor
 virtual ~ios_base();
 
 // callbacks
 enum event { erase_event, imbue_event, copyfmt_event };
 using event_callback = void (*)(event, ios_base&, int idx);
 void register_callback(event_callback fn, int idx);
 
 ios_base(const ios_base&) = delete;
 ios_base& operator=(const ios_base&) = delete;
 
 static bool sync_with_stdio(bool sync = true);
 
 protected:
 ios_base();
 
 private:
 static int index; // exposition only
 long* iarray; // exposition only
 void** parray; // exposition only
 };
}

namespace std {
 class ios_base::failure : public system_error {
 public:
 explicit failure(const string& msg, const error_code& ec = io_errc::stream);
 explicit failure(const char* msg, const error_code& ec = io_errc::stream);
 };
}

namespace std {
 class ios_base::Init {
 public:
 Init();
 Init(const Init&) = default;
 ~Init();
 Init& operator=(const Init&) = default;
 private:
 static int init_cnt; // exposition only
 };
}

namespace std {
 template<class StateT> class fpos {
 public:
 // members
 StateT state() const;
 void state(stateT);
 private;
 StateT st; // exposition only
 };
}

namespace std {
 template<class CharT, class Traits = char_traits<CharT>>
 class basic_ios : public ios_base {
 public:
 using char_type = CharT;
 using int_type = typename Traits::int_type;
 using pos_type = typename Traits::pos_type;
 using off_type = typename Traits::off_type;
 using traits_type = Traits;
 
 // flags functions
 explicit operator bool() const;
 bool operator!() const;
 iostate rdstate() const;
 void clear(iostate state = goodbit);
 void setstate(iostate state);
 bool good() const;
 bool eof() const;
 bool fail() const;
 bool bad() const;
 
 iostate exceptions() const;
 void exceptions(iostate except);
 
 // constructor/destructor
 explicit basic_ios(basic_streambuf<CharT, Traits>* sb);
 virtual ~basic_ios();
 
 // members
 basic_ostream<CharT, Traits>* tie() const;
 basic_ostream<CharT, Traits>* tie(basic_ostream<CharT, Traits>* tiestr);
 
 basic_streambuf<CharT, Traits>* rdbuf() const;
 basic_streambuf<CharT, Traits>* rdbuf(basic_streambuf<CharT, Traits>* sb);
 
 basic_ios& copyfmt(const basic_ios& rhs);
 
 char_type fill() const;
 char_type fill(char_type ch);
 
 locale imbue(const locale& loc);
 
 char narrow(char_type c, char dfault) const;
 char_type widen(char c) const;
 
 basic_ios(const basic_ios&) = delete;
 basic_ios& operator=(const basic_ios&) = delete;
 
 protected:
 basic_ios();
 void init(basic_streambuf<CharT, Traits>* sb);
 void move(basic_ios& rhs);
 void move(basic_ios&& rhs);
 void swap(basic_ios& rhs) noexcept;
 void set_rdbuf(basic_streambuf<CharT, Traits>* sb);
 };
}