freebsd-dev/contrib/libstdc++/include/bits/ios_base.h
2003-07-11 03:42:04 +00:00

859 lines
25 KiB
C++

// Iostreams base classes -*- C++ -*-
// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003
// Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING. If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
// As a special exception, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License. This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
//
// ISO C++ 14882: 27.8 File-based streams
//
/** @file ios_base.h
* This is an internal header file, included by other library headers.
* You should not attempt to use it directly.
*/
#ifndef _CPP_BITS_IOSBASE_H
#define _CPP_BITS_IOSBASE_H 1
#pragma GCC system_header
#include <bits/atomicity.h>
#include <bits/localefwd.h>
#include <bits/locale_classes.h>
namespace std
{
// The following definitions of bitmask types are enums, not ints,
// as permitted (but not required) in the standard, in order to provide
// better type safety in iostream calls. A side effect is that
// expressions involving them are no longer compile-time constants.
enum _Ios_Fmtflags { _M_ios_fmtflags_end = 1L << 16 };
inline _Ios_Fmtflags
operator&(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
{ return _Ios_Fmtflags(static_cast<int>(__a) & static_cast<int>(__b)); }
inline _Ios_Fmtflags
operator|(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
{ return _Ios_Fmtflags(static_cast<int>(__a) | static_cast<int>(__b)); }
inline _Ios_Fmtflags
operator^(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
{ return _Ios_Fmtflags(static_cast<int>(__a) ^ static_cast<int>(__b)); }
inline _Ios_Fmtflags
operator|=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
{ return __a = __a | __b; }
inline _Ios_Fmtflags
operator&=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
{ return __a = __a & __b; }
inline _Ios_Fmtflags
operator^=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
{ return __a = __a ^ __b; }
inline _Ios_Fmtflags
operator~(_Ios_Fmtflags __a)
{ return _Ios_Fmtflags(~static_cast<int>(__a)); }
enum _Ios_Openmode { _M_ios_openmode_end = 1L << 16 };
inline _Ios_Openmode
operator&(_Ios_Openmode __a, _Ios_Openmode __b)
{ return _Ios_Openmode(static_cast<int>(__a) & static_cast<int>(__b)); }
inline _Ios_Openmode
operator|(_Ios_Openmode __a, _Ios_Openmode __b)
{ return _Ios_Openmode(static_cast<int>(__a) | static_cast<int>(__b)); }
inline _Ios_Openmode
operator^(_Ios_Openmode __a, _Ios_Openmode __b)
{ return _Ios_Openmode(static_cast<int>(__a) ^ static_cast<int>(__b)); }
inline _Ios_Openmode
operator|=(_Ios_Openmode& __a, _Ios_Openmode __b)
{ return __a = __a | __b; }
inline _Ios_Openmode
operator&=(_Ios_Openmode& __a, _Ios_Openmode __b)
{ return __a = __a & __b; }
inline _Ios_Openmode
operator^=(_Ios_Openmode& __a, _Ios_Openmode __b)
{ return __a = __a ^ __b; }
inline _Ios_Openmode
operator~(_Ios_Openmode __a)
{ return _Ios_Openmode(~static_cast<int>(__a)); }
enum _Ios_Iostate { _M_ios_iostate_end = 1L << 16 };
inline _Ios_Iostate
operator&(_Ios_Iostate __a, _Ios_Iostate __b)
{ return _Ios_Iostate(static_cast<int>(__a) & static_cast<int>(__b)); }
inline _Ios_Iostate
operator|(_Ios_Iostate __a, _Ios_Iostate __b)
{ return _Ios_Iostate(static_cast<int>(__a) | static_cast<int>(__b)); }
inline _Ios_Iostate
operator^(_Ios_Iostate __a, _Ios_Iostate __b)
{ return _Ios_Iostate(static_cast<int>(__a) ^ static_cast<int>(__b)); }
inline _Ios_Iostate
operator|=(_Ios_Iostate& __a, _Ios_Iostate __b)
{ return __a = __a | __b; }
inline _Ios_Iostate
operator&=(_Ios_Iostate& __a, _Ios_Iostate __b)
{ return __a = __a & __b; }
inline _Ios_Iostate
operator^=(_Ios_Iostate& __a, _Ios_Iostate __b)
{ return __a = __a ^ __b; }
inline _Ios_Iostate
operator~(_Ios_Iostate __a)
{ return _Ios_Iostate(~static_cast<int>(__a)); }
enum _Ios_Seekdir { _M_ios_seekdir_end = 1L << 16 };
// 27.4.2 Class ios_base
/**
* @brief The very top of the I/O class hierarchy.
*
* This class defines everything that can be defined about I/O that does
* not depend on the type of characters being input or output. Most
* people will only see @c ios_base when they need to specify the full
* name of the various I/O flags (e.g., the openmodes).
*/
class ios_base
{
public:
// 27.4.2.1.1 Class ios_base::failure
/// These are thrown to indicate problems. Doc me.
class failure : public exception
{
public:
#ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
//48. Use of non-existent exception constructor
explicit
failure(const string& __str) throw();
// This declaration is not useless:
// http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
virtual
~failure() throw();
virtual const char*
what() const throw();
private:
enum { _M_bufsize = 256 };
char _M_name[_M_bufsize];
#endif
};
// 27.4.2.1.2 Type ios_base::fmtflags
/**
* @brief This is a bitmask type.
*
* @c "_Ios_Fmtflags" is implementation-defined, but it is valid to
* perform bitwise operations on these values and expect the Right
* Thing to happen. Defined objects of type fmtflags are:
* - boolalpha
* - dec
* - fixed
* - hex
* - internal
* - left
* - oct
* - right
* - scientific
* - showbase
* - showpoint
* - showpos
* - skipws
* - unitbuf
* - uppercase
* - adjustfield
* - basefield
* - floatfield
*/
typedef _Ios_Fmtflags fmtflags;
/// Insert/extract @c bool in alphabetic rather than numeric format.
static const fmtflags boolalpha = fmtflags(__ios_flags::_S_boolalpha);
/// Converts integer input or generates integer output in decimal base.
static const fmtflags dec = fmtflags(__ios_flags::_S_dec);
/// Generate floating-point output in fixed-point notation.
static const fmtflags fixed = fmtflags(__ios_flags::_S_fixed);
/// Converts integer input or generates integer output in hexadecimal base.
static const fmtflags hex = fmtflags(__ios_flags::_S_hex);
/// Adds fill characters at a designated internal point in certain
/// generated output, or identical to @c right if no such point is
/// designated.
static const fmtflags internal = fmtflags(__ios_flags::_S_internal);
/// Adds fill characters on the right (final positions) of certain
/// generated output. (I.e., the thing you print is flush left.)
static const fmtflags left = fmtflags(__ios_flags::_S_left);
/// Converts integer input or generates integer output in octal base.
static const fmtflags oct = fmtflags(__ios_flags::_S_oct);
/// Adds fill characters on the left (initial positions) of certain
/// generated output. (I.e., the thing you print is flush right.)
static const fmtflags right = fmtflags(__ios_flags::_S_right);
/// Generates floating-point output in scientific notation.
static const fmtflags scientific = fmtflags(__ios_flags::_S_scientific);
/// Generates a prefix indicating the numeric base of generated integer
/// output.
static const fmtflags showbase = fmtflags(__ios_flags::_S_showbase);
/// Generates a decimal-point character unconditionally in generated
/// floating-point output.
static const fmtflags showpoint = fmtflags(__ios_flags::_S_showpoint);
/// Generates a + sign in non-negative generated numeric output.
static const fmtflags showpos = fmtflags(__ios_flags::_S_showpos);
/// Skips leading white space before certain input operations.
static const fmtflags skipws = fmtflags(__ios_flags::_S_skipws);
/// Flushes output after each output operation.
static const fmtflags unitbuf = fmtflags(__ios_flags::_S_unitbuf);
/// Replaces certain lowercase letters with their uppercase equivalents
/// in generated output.
static const fmtflags uppercase = fmtflags(__ios_flags::_S_uppercase);
/// A mask of left|right|internal. Useful for the 2-arg form of @c setf.
static const fmtflags adjustfield = fmtflags(__ios_flags::_S_adjustfield);
/// A mask of dec|oct|hex. Useful for the 2-arg form of @c setf.
static const fmtflags basefield = fmtflags(__ios_flags::_S_basefield);
/// A mask of scientific|fixed. Useful for the 2-arg form of @c setf.
static const fmtflags floatfield = fmtflags(__ios_flags::_S_floatfield);
// 27.4.2.1.3 Type ios_base::iostate
/**
* @brief This is a bitmask type.
*
* @c "_Ios_Iostate" is implementation-defined, but it is valid to
* perform bitwise operations on these values and expect the Right
* Thing to happen. Defined objects of type iostate are:
* - badbit
* - eofbit
* - failbit
* - goodbit
*/
typedef _Ios_Iostate iostate;
/// Indicates a loss of integrity in an input or output sequence (such
/// as an irrecoverable read error from a file).
static const iostate badbit = iostate(__ios_flags::_S_badbit);
/// Indicates that an input operation reached the end of an input sequence.
static const iostate eofbit = iostate(__ios_flags::_S_eofbit);
/// Indicates that an input operation failed to read the expected
/// characters, or that an output operation failed to generate the
/// desired characters.
static const iostate failbit = iostate(__ios_flags::_S_failbit);
/// Indicates all is well.
static const iostate goodbit = iostate(0);
// 27.4.2.1.4 Type ios_base::openmode
/**
* @brief This is a bitmask type.
*
* @c "_Ios_Openmode" is implementation-defined, but it is valid to
* perform bitwise operations on these values and expect the Right
* Thing to happen. Defined objects of type openmode are:
* - app
* - ate
* - binary
* - in
* - out
* - trunc
*/
typedef _Ios_Openmode openmode;
/// Seek to end before each write.
static const openmode app = openmode(__ios_flags::_S_app);
/// Open and seek to end immediately after opening.
static const openmode ate = openmode(__ios_flags::_S_ate);
/// Perform input and output in binary mode (as opposed to text mode).
/// This is probably not what you think it is; see
/// http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#3 and
/// http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#7 for more.
static const openmode binary = openmode(__ios_flags::_S_bin);
/// Open for input. Default for @c ifstream and fstream.
static const openmode in = openmode(__ios_flags::_S_in);
/// Open for output. Default for @c ofstream and fstream.
static const openmode out = openmode(__ios_flags::_S_out);
/// Open for input. Default for @c ofstream.
static const openmode trunc = openmode(__ios_flags::_S_trunc);
// 27.4.2.1.5 Type ios_base::seekdir
/**
* @brief This is an enumerated type.
*
* @c "_Ios_Seekdir" is implementation-defined. Defined values
* of type seekdir are:
* - beg
* - cur, equivalent to @c SEEK_CUR in the C standard library.
* - end, equivalent to @c SEEK_END in the C standard library.
*/
typedef _Ios_Seekdir seekdir;
/// Request a seek relative to the beginning of the stream.
static const seekdir beg = seekdir(0);
/// Request a seek relative to the current position within the sequence.
static const seekdir cur = seekdir(SEEK_CUR);
/// Request a seek relative to the current end of the sequence.
static const seekdir end = seekdir(SEEK_END);
#ifdef _GLIBCPP_DEPRECATED
// Annex D.6
typedef int io_state;
typedef int open_mode;
typedef int seek_dir;
typedef std::streampos streampos;
typedef std::streamoff streamoff;
#endif
// Callbacks;
/**
* @doctodo
*/
enum event
{
erase_event,
imbue_event,
copyfmt_event
};
/**
* @doctodo
*/
typedef void (*event_callback) (event, ios_base&, int);
/**
* @doctodo
*/
void
register_callback(event_callback __fn, int __index);
protected:
//@{
/**
* @if maint
* ios_base data members (doc me)
* @endif
*/
streamsize _M_precision;
streamsize _M_width;
fmtflags _M_flags;
iostate _M_exception;
iostate _M_streambuf_state;
//@}
// 27.4.2.6 Members for callbacks
// 27.4.2.6 ios_base callbacks
struct _Callback_list
{
// Data Members
_Callback_list* _M_next;
ios_base::event_callback _M_fn;
int _M_index;
_Atomic_word _M_refcount; // 0 means one reference.
_Callback_list(ios_base::event_callback __fn, int __index,
_Callback_list* __cb)
: _M_next(__cb), _M_fn(__fn), _M_index(__index), _M_refcount(0) { }
void
_M_add_reference() { __atomic_add(&_M_refcount, 1); }
// 0 => OK to delete.
int
_M_remove_reference() { return __exchange_and_add(&_M_refcount, -1); }
};
_Callback_list* _M_callbacks;
void
_M_call_callbacks(event __ev) throw();
void
_M_dispose_callbacks(void);
// 27.4.2.5 Members for iword/pword storage
struct _Words
{
void* _M_pword;
long _M_iword;
_Words() : _M_pword(0), _M_iword(0) { }
};
// Only for failed iword/pword calls.
_Words _M_word_zero;
// Guaranteed storage.
// The first 5 iword and pword slots are reserved for internal use.
static const int _S_local_word_size = 8;
_Words _M_local_word[_S_local_word_size];
// Allocated storage.
int _M_word_size;
_Words* _M_word;
_Words&
_M_grow_words(int __index);
// Members for locale and locale caching.
locale _M_ios_locale;
void
_M_init();
public:
// 27.4.2.1.6 Class ios_base::Init
// Used to initialize standard streams. In theory, g++ could use
// -finit-priority to order this stuff correctly without going
// through these machinations.
class Init
{
friend class ios_base;
public:
Init();
~Init();
static void
_S_ios_create(bool __sync);
static void
_S_ios_destroy();
// NB: Allows debugger applications use of the standard streams
// from operator new. _S_ios_base_init must be incremented in
// _S_ios_create _after_ initialization is completed.
static bool
_S_initialized() { return _S_ios_base_init; }
private:
static int _S_ios_base_init;
static bool _S_synced_with_stdio;
};
// [27.4.2.2] fmtflags state functions
/**
* @brief Access to format flags.
* @return The format control flags for both input and output.
*/
inline fmtflags
flags() const { return _M_flags; }
/**
* @brief Setting new format flags all at once.
* @param fmtfl The new flags to set.
* @return The previous format control flags.
*
* This function overwrites all the format flags with @a fmtfl.
*/
inline fmtflags
flags(fmtflags __fmtfl)
{
fmtflags __old = _M_flags;
_M_flags = __fmtfl;
return __old;
}
/**
* @brief Setting new format flags.
* @param fmtfl Additional flags to set.
* @return The previous format control flags.
*
* This function sets additional flags in format control. Flags that
* were previously set remain set.
*/
inline fmtflags
setf(fmtflags __fmtfl)
{
fmtflags __old = _M_flags;
_M_flags |= __fmtfl;
return __old;
}
/**
* @brief Setting new format flags.
* @param fmtfl Additional flags to set.
* @param mask The flags mask for @a fmtfl.
* @return The previous format control flags.
*
* This function clears @a mask in the format flags, then sets
* @a fmtfl @c & @a mask. An example mask is @c ios_base::adjustfield.
*/
inline fmtflags
setf(fmtflags __fmtfl, fmtflags __mask)
{
fmtflags __old = _M_flags;
_M_flags &= ~__mask;
_M_flags |= (__fmtfl & __mask);
return __old;
}
/**
* @brief Clearing format flags.
* @param mask The flags to unset.
*
* This function clears @a mask in the format flags.
*/
inline void
unsetf(fmtflags __mask) { _M_flags &= ~__mask; }
/**
* @brief Flags access.
* @return The precision to generate on certain output operations.
*
* @if maint
* Be careful if you try to give a definition of "precision" here; see
* DR 189.
* @endif
*/
inline streamsize
precision() const { return _M_precision; }
/**
* @brief Changing flags.
* @param prec The new precision value.
* @return The previous value of precision().
*/
inline streamsize
precision(streamsize __prec)
{
streamsize __old = _M_precision;
_M_precision = __prec;
return __old;
}
/**
* @brief Flags access.
* @return The minimum field width to generate on output operations.
*
* "Minimum field width" refers to the number of characters.
*/
inline streamsize
width() const { return _M_width; }
/**
* @brief Changing flags.
* @param wide The new width value.
* @return The previous value of width().
*/
inline streamsize
width(streamsize __wide)
{
streamsize __old = _M_width;
_M_width = __wide;
return __old;
}
// [27.4.2.4] ios_base static members
/**
* @brief Interaction with the standard C I/O objects.
* @param sync Whether to synchronize or not.
* @return True if the standard streams were previously synchronized.
*
* The synchronization referred to is @e only that between the standard
* C facilities (e.g., stdout) and the standard C++ objects (e.g.,
* cout). User-declared streams are unaffected. See
* http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#8 for more.
*/
static bool
sync_with_stdio(bool __sync = true);
// [27.4.2.3] ios_base locale functions
/**
* @brief Setting a new locale.
* @param loc The new locale.
* @return The previous locale.
*
* Sets the new locale for this stream, and
* [XXX does something with callbacks].
*/
locale
imbue(const locale& __loc);
/**
* @brief Locale access
* @return A copy of the current locale.
*
* If @c imbue(loc) has previously been called, then this function
* returns @c loc. Otherwise, it returns a copy of @c std::locale(),
* the global C++ locale.
*/
inline locale
getloc() const { return _M_ios_locale; }
/**
* @brief Locale access
* @return A reference to the current locale.
*
* Like getloc above, but returns a reference instead of
* generating a copy.
*/
inline const locale&
_M_getloc() const { return _M_ios_locale; }
// [27.4.2.5] ios_base storage functions
/**
* @doctodo
*/
static int
xalloc() throw();
/**
* @doctodo
*/
inline long&
iword(int __ix)
{
_Words& __word = (__ix < _M_word_size)
? _M_word[__ix] : _M_grow_words(__ix);
return __word._M_iword;
}
/**
* @doctodo
*/
inline void*&
pword(int __ix)
{
_Words& __word = (__ix < _M_word_size)
? _M_word[__ix] : _M_grow_words(__ix);
return __word._M_pword;
}
// Destructor
/**
* Destroys local storage and
* [XXX does something with callbacks].
*/
~ios_base();
protected:
ios_base();
#ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
//50. Copy constructor and assignment operator of ios_base
private:
ios_base(const ios_base&);
ios_base&
operator=(const ios_base&);
#endif
};
// [27.4.5.1] fmtflags manipulators
/// Calls base.setf(ios_base::boolalpha).
inline ios_base&
boolalpha(ios_base& __base)
{
__base.setf(ios_base::boolalpha);
return __base;
}
/// Calls base.unsetf(ios_base::boolalpha).
inline ios_base&
noboolalpha(ios_base& __base)
{
__base.unsetf(ios_base::boolalpha);
return __base;
}
/// Calls base.setf(ios_base::showbase).
inline ios_base&
showbase(ios_base& __base)
{
__base.setf(ios_base::showbase);
return __base;
}
/// Calls base.unsetf(ios_base::showbase).
inline ios_base&
noshowbase(ios_base& __base)
{
__base.unsetf(ios_base::showbase);
return __base;
}
/// Calls base.setf(ios_base::showpoint).
inline ios_base&
showpoint(ios_base& __base)
{
__base.setf(ios_base::showpoint);
return __base;
}
/// Calls base.unsetf(ios_base::showpoint).
inline ios_base&
noshowpoint(ios_base& __base)
{
__base.unsetf(ios_base::showpoint);
return __base;
}
/// Calls base.setf(ios_base::showpos).
inline ios_base&
showpos(ios_base& __base)
{
__base.setf(ios_base::showpos);
return __base;
}
/// Calls base.unsetf(ios_base::showpos).
inline ios_base&
noshowpos(ios_base& __base)
{
__base.unsetf(ios_base::showpos);
return __base;
}
/// Calls base.setf(ios_base::skipws).
inline ios_base&
skipws(ios_base& __base)
{
__base.setf(ios_base::skipws);
return __base;
}
/// Calls base.unsetf(ios_base::skipws).
inline ios_base&
noskipws(ios_base& __base)
{
__base.unsetf(ios_base::skipws);
return __base;
}
/// Calls base.setf(ios_base::uppercase).
inline ios_base&
uppercase(ios_base& __base)
{
__base.setf(ios_base::uppercase);
return __base;
}
/// Calls base.unsetf(ios_base::uppercase).
inline ios_base&
nouppercase(ios_base& __base)
{
__base.unsetf(ios_base::uppercase);
return __base;
}
/// Calls base.setf(ios_base::unitbuf).
inline ios_base&
unitbuf(ios_base& __base)
{
__base.setf(ios_base::unitbuf);
return __base;
}
/// Calls base.unsetf(ios_base::unitbuf).
inline ios_base&
nounitbuf(ios_base& __base)
{
__base.unsetf(ios_base::unitbuf);
return __base;
}
// [27.4.5.2] adjustfield anipulators
/// Calls base.setf(ios_base::internal, ios_base::adjustfield).
inline ios_base&
internal(ios_base& __base)
{
__base.setf(ios_base::internal, ios_base::adjustfield);
return __base;
}
/// Calls base.setf(ios_base::left, ios_base::adjustfield).
inline ios_base&
left(ios_base& __base)
{
__base.setf(ios_base::left, ios_base::adjustfield);
return __base;
}
/// Calls base.setf(ios_base::right, ios_base::adjustfield).
inline ios_base&
right(ios_base& __base)
{
__base.setf(ios_base::right, ios_base::adjustfield);
return __base;
}
// [27.4.5.3] basefield anipulators
/// Calls base.setf(ios_base::dec, ios_base::basefield).
inline ios_base&
dec(ios_base& __base)
{
__base.setf(ios_base::dec, ios_base::basefield);
return __base;
}
/// Calls base.setf(ios_base::hex, ios_base::basefield).
inline ios_base&
hex(ios_base& __base)
{
__base.setf(ios_base::hex, ios_base::basefield);
return __base;
}
/// Calls base.setf(ios_base::oct, ios_base::basefield).
inline ios_base&
oct(ios_base& __base)
{
__base.setf(ios_base::oct, ios_base::basefield);
return __base;
}
// [27.4.5.4] floatfield anipulators
/// Calls base.setf(ios_base::fixed, ios_base::floatfield).
inline ios_base&
fixed(ios_base& __base)
{
__base.setf(ios_base::fixed, ios_base::floatfield);
return __base;
}
/// Calls base.setf(ios_base::scientific, ios_base::floatfield).
inline ios_base&
scientific(ios_base& __base)
{
__base.setf(ios_base::scientific, ios_base::floatfield);
return __base;
}
} // namespace std
#endif /* _CPP_BITS_IOSBASE_H */