libstdc++
iomanip
Go to the documentation of this file.
1 // Standard stream manipulators -*- C++ -*-
2 
3 // Copyright (C) 1997-2025 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /** @file include/iomanip
26  * This is a Standard C++ Library header.
27  */
28 
29 //
30 // ISO C++ 14882: 27.6.3 Standard manipulators
31 //
32 
33 #ifndef _GLIBCXX_IOMANIP
34 #define _GLIBCXX_IOMANIP 1
35 
36 #ifdef _GLIBCXX_SYSHDR
37 #pragma GCC system_header
38 #endif
39 
40 #pragma GCC diagnostic push
41 #pragma GCC diagnostic ignored "-Wc++11-extensions"
42 
43 #include <bits/requires_hosted.h> // iostreams
44 
45 #include <bits/c++config.h>
46 #include <iosfwd>
47 #include <bits/ios_base.h>
48 
49 #define __glibcxx_want_quoted_string_io
50 #include <bits/version.h>
51 
52 #if __cplusplus >= 201103L
53 #include <locale>
54 #if __cplusplus > 201103L
55 #include <bits/quoted_string.h>
56 #endif
57 #endif
58 
59 namespace std _GLIBCXX_VISIBILITY(default)
60 {
61 _GLIBCXX_BEGIN_NAMESPACE_VERSION
62 
63  // [27.6.3] standard manipulators
64  // Also see DR 183.
65 
66  struct _Resetiosflags { ios_base::fmtflags _M_mask; };
67 
68  /**
69  * @brief Manipulator for @c setf.
70  * @param __mask A format flags mask.
71  *
72  * Sent to a stream object, this manipulator resets the specified flags,
73  * via @e stream.setf(0,__mask).
74  */
75  inline _Resetiosflags
76  resetiosflags(ios_base::fmtflags __mask)
77  { return { __mask }; }
78 
79  template<typename _CharT, typename _Traits>
80  inline basic_istream<_CharT, _Traits>&
81  operator>>(basic_istream<_CharT, _Traits>& __is, _Resetiosflags __f)
82  {
83  __is.setf(ios_base::fmtflags(0), __f._M_mask);
84  return __is;
85  }
86 
87  template<typename _CharT, typename _Traits>
88  inline basic_ostream<_CharT, _Traits>&
89  operator<<(basic_ostream<_CharT, _Traits>& __os, _Resetiosflags __f)
90  {
91  __os.setf(ios_base::fmtflags(0), __f._M_mask);
92  return __os;
93  }
94 
95 
96  struct _Setiosflags { ios_base::fmtflags _M_mask; };
97 
98  /**
99  * @brief Manipulator for @c setf.
100  * @param __mask A format flags mask.
101  *
102  * Sent to a stream object, this manipulator sets the format flags
103  * to @a __mask.
104  */
105  inline _Setiosflags
106  setiosflags(ios_base::fmtflags __mask)
107  { return { __mask }; }
108 
109  template<typename _CharT, typename _Traits>
110  inline basic_istream<_CharT, _Traits>&
111  operator>>(basic_istream<_CharT, _Traits>& __is, _Setiosflags __f)
112  {
113  __is.setf(__f._M_mask);
114  return __is;
115  }
116 
117  template<typename _CharT, typename _Traits>
118  inline basic_ostream<_CharT, _Traits>&
119  operator<<(basic_ostream<_CharT, _Traits>& __os, _Setiosflags __f)
120  {
121  __os.setf(__f._M_mask);
122  return __os;
123  }
124 
125 
126  struct _Setbase { int _M_base; };
127 
128  /**
129  * @brief Manipulator for @c setf.
130  * @param __base A numeric base.
131  *
132  * Sent to a stream object, this manipulator changes the
133  * @c ios_base::basefield flags to @c oct, @c dec, or @c hex when @a base
134  * is 8, 10, or 16, accordingly, and to 0 if @a __base is any other value.
135  */
136  inline _Setbase
137  setbase(int __base)
138  { return { __base }; }
139 
140  template<typename _CharT, typename _Traits>
141  inline basic_istream<_CharT, _Traits>&
142  operator>>(basic_istream<_CharT, _Traits>& __is, _Setbase __f)
143  {
144  __is.setf(__f._M_base == 8 ? ios_base::oct :
145  __f._M_base == 10 ? ios_base::dec :
146  __f._M_base == 16 ? ios_base::hex :
147  ios_base::fmtflags(0), ios_base::basefield);
148  return __is;
149  }
150 
151  template<typename _CharT, typename _Traits>
152  inline basic_ostream<_CharT, _Traits>&
153  operator<<(basic_ostream<_CharT, _Traits>& __os, _Setbase __f)
154  {
155  __os.setf(__f._M_base == 8 ? ios_base::oct :
156  __f._M_base == 10 ? ios_base::dec :
157  __f._M_base == 16 ? ios_base::hex :
158  ios_base::fmtflags(0), ios_base::basefield);
159  return __os;
160  }
161 
162 
163  template<typename _CharT>
164  struct _Setfill { _CharT _M_c; };
165 
166  /**
167  * @brief Manipulator for @c fill.
168  * @param __c The new fill character.
169  *
170  * Sent to a stream object, this manipulator calls @c fill(__c) for that
171  * object.
172  */
173  template<typename _CharT>
174  inline _Setfill<_CharT>
175  setfill(_CharT __c)
176  { return { __c }; }
177 
178  template<typename _CharT, typename _Traits>
179  __attribute__((__deprecated__("'std::setfill' should only be used with "
180  "output streams")))
181  inline basic_istream<_CharT, _Traits>&
182  operator>>(basic_istream<_CharT, _Traits>& __is, _Setfill<_CharT> __f)
183  {
184  __is.fill(__f._M_c);
185  return __is;
186  }
187 
188  template<typename _CharT, typename _Traits>
189  inline basic_ostream<_CharT, _Traits>&
190  operator<<(basic_ostream<_CharT, _Traits>& __os, _Setfill<_CharT> __f)
191  {
192  __os.fill(__f._M_c);
193  return __os;
194  }
195 
196 
197  struct _Setprecision { int _M_n; };
198 
199  /**
200  * @brief Manipulator for @c precision.
201  * @param __n The new precision.
202  *
203  * Sent to a stream object, this manipulator calls @c precision(__n) for
204  * that object.
205  */
206  inline _Setprecision
207  setprecision(int __n)
208  { return { __n }; }
209 
210  template<typename _CharT, typename _Traits>
211  inline basic_istream<_CharT, _Traits>&
212  operator>>(basic_istream<_CharT, _Traits>& __is, _Setprecision __f)
213  {
214  __is.precision(__f._M_n);
215  return __is;
216  }
217 
218  template<typename _CharT, typename _Traits>
219  inline basic_ostream<_CharT, _Traits>&
220  operator<<(basic_ostream<_CharT, _Traits>& __os, _Setprecision __f)
221  {
222  __os.precision(__f._M_n);
223  return __os;
224  }
225 
226 
227  struct _Setw { int _M_n; };
228 
229  /**
230  * @brief Manipulator for @c width.
231  * @param __n The new width.
232  *
233  * Sent to a stream object, this manipulator calls @c width(__n) for
234  * that object.
235  */
236  inline _Setw
237  setw(int __n)
238  { return { __n }; }
239 
240  template<typename _CharT, typename _Traits>
241  inline basic_istream<_CharT, _Traits>&
242  operator>>(basic_istream<_CharT, _Traits>& __is, _Setw __f)
243  {
244  __is.width(__f._M_n);
245  return __is;
246  }
247 
248  template<typename _CharT, typename _Traits>
249  inline basic_ostream<_CharT, _Traits>&
250  operator<<(basic_ostream<_CharT, _Traits>& __os, _Setw __f)
251  {
252  __os.width(__f._M_n);
253  return __os;
254  }
255 
256 #if __cplusplus >= 201103L
257 
258  template<typename _MoneyT>
259  struct _Get_money { _MoneyT& _M_mon; bool _M_intl; };
260 
261  /**
262  * @brief Extended manipulator for extracting money.
263  * @param __mon Either long double or a specialization of @c basic_string.
264  * @param __intl A bool indicating whether international format
265  * is to be used.
266  *
267  * Sent to a stream object, this manipulator extracts @a __mon.
268  */
269  template<typename _MoneyT>
270  inline _Get_money<_MoneyT>
271  get_money(_MoneyT& __mon, bool __intl = false)
272  { return { __mon, __intl }; }
273 
274  template<typename _CharT, typename _Traits, typename _MoneyT>
275  basic_istream<_CharT, _Traits>&
276  operator>>(basic_istream<_CharT, _Traits>& __is, _Get_money<_MoneyT> __f)
277  {
278  typename basic_istream<_CharT, _Traits>::sentry __cerb(__is, false);
279  if (__cerb)
280  {
281  ios_base::iostate __err = ios_base::goodbit;
282  __try
283  {
284  typedef istreambuf_iterator<_CharT, _Traits> _Iter;
285  typedef money_get<_CharT, _Iter> _MoneyGet;
286 
287  const _MoneyGet& __mg = use_facet<_MoneyGet>(__is.getloc());
288  __mg.get(_Iter(__is.rdbuf()), _Iter(), __f._M_intl,
289  __is, __err, __f._M_mon);
290  }
291  __catch(__cxxabiv1::__forced_unwind&)
292  {
293  __is._M_setstate(ios_base::badbit);
294  __throw_exception_again;
295  }
296  __catch(...)
297  { __is._M_setstate(ios_base::badbit); }
298  if (__err)
299  __is.setstate(__err);
300  }
301  return __is;
302  }
303 
304 
305  template<typename _MoneyT>
306  struct _Put_money { const _MoneyT& _M_mon; bool _M_intl; };
307 
308  /**
309  * @brief Extended manipulator for inserting money.
310  * @param __mon Either long double or a specialization of @c basic_string.
311  * @param __intl A bool indicating whether international format
312  * is to be used.
313  *
314  * Sent to a stream object, this manipulator inserts @a __mon.
315  */
316  template<typename _MoneyT>
317  inline _Put_money<_MoneyT>
318  put_money(const _MoneyT& __mon, bool __intl = false)
319  { return { __mon, __intl }; }
320 
321  template<typename _CharT, typename _Traits, typename _MoneyT>
322  basic_ostream<_CharT, _Traits>&
323  operator<<(basic_ostream<_CharT, _Traits>& __os, _Put_money<_MoneyT> __f)
324  {
325  typename basic_ostream<_CharT, _Traits>::sentry __cerb(__os);
326  if (__cerb)
327  {
328  ios_base::iostate __err = ios_base::goodbit;
329  __try
330  {
331  typedef ostreambuf_iterator<_CharT, _Traits> _Iter;
332  typedef money_put<_CharT, _Iter> _MoneyPut;
333 
334  const _MoneyPut& __mp = use_facet<_MoneyPut>(__os.getloc());
335  if (__mp.put(_Iter(__os.rdbuf()), __f._M_intl, __os,
336  __os.fill(), __f._M_mon).failed())
337  __err |= ios_base::badbit;
338  }
339  __catch(__cxxabiv1::__forced_unwind&)
340  {
341  __os._M_setstate(ios_base::badbit);
342  __throw_exception_again;
343  }
344  __catch(...)
345  { __os._M_setstate(ios_base::badbit); }
346  if (__err)
347  __os.setstate(__err);
348  }
349  return __os;
350  }
351 
352  template<typename _CharT>
353  struct _Put_time
354  {
355  const std::tm* _M_tmb;
356  const _CharT* _M_fmt;
357  };
358 
359  /**
360  * @brief Extended manipulator for formatting time.
361  *
362  * This manipulator uses time_put::put to format time.
363  * [ext.manip]
364  *
365  * @param __tmb struct tm time data to format.
366  * @param __fmt format string.
367  */
368  template<typename _CharT>
369  inline _Put_time<_CharT>
370  put_time(const std::tm* __tmb, const _CharT* __fmt)
371  { return { __tmb, __fmt }; }
372 
373  template<typename _CharT, typename _Traits>
374  basic_ostream<_CharT, _Traits>&
375  operator<<(basic_ostream<_CharT, _Traits>& __os, _Put_time<_CharT> __f)
376  {
377  typename basic_ostream<_CharT, _Traits>::sentry __cerb(__os);
378  if (__cerb)
379  {
380  ios_base::iostate __err = ios_base::goodbit;
381  __try
382  {
383  typedef ostreambuf_iterator<_CharT, _Traits> _Iter;
384  typedef time_put<_CharT, _Iter> _TimePut;
385 
386  const _CharT* const __fmt_end = __f._M_fmt +
387  _Traits::length(__f._M_fmt);
388 
389  const _TimePut& __mp = use_facet<_TimePut>(__os.getloc());
390  if (__mp.put(_Iter(__os.rdbuf()), __os, __os.fill(),
391  __f._M_tmb, __f._M_fmt, __fmt_end).failed())
392  __err |= ios_base::badbit;
393  }
394  __catch(__cxxabiv1::__forced_unwind&)
395  {
396  __os._M_setstate(ios_base::badbit);
397  __throw_exception_again;
398  }
399  __catch(...)
400  { __os._M_setstate(ios_base::badbit); }
401  if (__err)
402  __os.setstate(__err);
403  }
404  return __os;
405  }
406 
407  template<typename _CharT>
408  struct _Get_time
409  {
410  std::tm* _M_tmb;
411  const _CharT* _M_fmt;
412  };
413 
414  /**
415  * @brief Extended manipulator for extracting time.
416  *
417  * This manipulator uses time_get::get to extract time.
418  * [ext.manip]
419  *
420  * @param __tmb struct to extract the time data to.
421  * @param __fmt format string.
422  */
423  template<typename _CharT>
424  inline _Get_time<_CharT>
425  get_time(std::tm* __tmb, const _CharT* __fmt)
426  { return { __tmb, __fmt }; }
427 
428  template<typename _CharT, typename _Traits>
429  basic_istream<_CharT, _Traits>&
430  operator>>(basic_istream<_CharT, _Traits>& __is, _Get_time<_CharT> __f)
431  {
432  typename basic_istream<_CharT, _Traits>::sentry __cerb(__is, false);
433  if (__cerb)
434  {
435  ios_base::iostate __err = ios_base::goodbit;
436  __try
437  {
438  typedef istreambuf_iterator<_CharT, _Traits> _Iter;
439  typedef time_get<_CharT, _Iter> _TimeGet;
440 
441  const _CharT* const __fmt_end = __f._M_fmt +
442  _Traits::length(__f._M_fmt);
443 
444  const _TimeGet& __mg = use_facet<_TimeGet>(__is.getloc());
445  __mg.get(_Iter(__is.rdbuf()), _Iter(), __is,
446  __err, __f._M_tmb, __f._M_fmt, __fmt_end);
447  }
448  __catch(__cxxabiv1::__forced_unwind&)
449  {
450  __is._M_setstate(ios_base::badbit);
451  __throw_exception_again;
452  }
453  __catch(...)
454  { __is._M_setstate(ios_base::badbit); }
455  if (__err)
456  __is.setstate(__err);
457  }
458  return __is;
459  }
460 
461 #ifdef __cpp_lib_quoted_string_io // C++ >= 14 && HOSTED
462 
463  /**
464  * @brief Manipulator for quoted strings.
465  * @param __string String to quote.
466  * @param __delim Character to quote string with.
467  * @param __escape Escape character to escape itself or quote character.
468  * @since C++14
469  */
470  template<typename _CharT>
471  inline auto
472  quoted(const _CharT* __string,
473  _CharT __delim = _CharT('"'), _CharT __escape = _CharT('\\'))
474  {
475  return __detail::_Quoted_string<const _CharT*, _CharT>(__string, __delim,
476  __escape);
477  }
478 
479  template<typename _CharT, typename _Traits, typename _Alloc>
480  inline auto
481  quoted(const basic_string<_CharT, _Traits, _Alloc>& __string,
482  _CharT __delim = _CharT('"'), _CharT __escape = _CharT('\\'))
483  {
484  return __detail::_Quoted_string<
485  const basic_string<_CharT, _Traits, _Alloc>&, _CharT>(
486  __string, __delim, __escape);
487  }
488 
489  template<typename _CharT, typename _Traits, typename _Alloc>
490  inline auto
491  quoted(basic_string<_CharT, _Traits, _Alloc>& __string,
492  _CharT __delim = _CharT('"'), _CharT __escape = _CharT('\\'))
493  {
494  return __detail::_Quoted_string<
495  basic_string<_CharT, _Traits, _Alloc>&, _CharT>(
496  __string, __delim, __escape);
497  }
498 
499 #if __cplusplus >= 201703L
500  // _GLIBCXX_RESOLVE_LIB_DEFECTS
501  // 2785. quoted should work with basic_string_view
502  template<typename _CharT, typename _Traits>
503  inline auto
504  quoted(basic_string_view<_CharT, _Traits> __sv,
505  _CharT __delim = _CharT('"'), _CharT __escape = _CharT('\\'))
506  {
507  return __detail::_Quoted_string<
508  basic_string_view<_CharT, _Traits>, _CharT>(__sv, __delim, __escape);
509  }
510 #endif // C++17
511 #endif // __cpp_lib_quoted_string_io
512 
513 #endif // __cplusplus >= 201103L
514 
515  // Inhibit implicit instantiations for required instantiations,
516  // which are defined via explicit instantiations elsewhere.
517  // NB: This syntax is a GNU extension.
518 #if _GLIBCXX_EXTERN_TEMPLATE
519  extern template ostream& operator<<(ostream&, _Setfill<char>);
520  extern template ostream& operator<<(ostream&, _Setiosflags);
521  extern template ostream& operator<<(ostream&, _Resetiosflags);
522  extern template ostream& operator<<(ostream&, _Setbase);
523  extern template ostream& operator<<(ostream&, _Setprecision);
524  extern template ostream& operator<<(ostream&, _Setw);
525  extern template istream& operator>>(istream&, _Setfill<char>);
526  extern template istream& operator>>(istream&, _Setiosflags);
527  extern template istream& operator>>(istream&, _Resetiosflags);
528  extern template istream& operator>>(istream&, _Setbase);
529  extern template istream& operator>>(istream&, _Setprecision);
530  extern template istream& operator>>(istream&, _Setw);
531 
532 #ifdef _GLIBCXX_USE_WCHAR_T
533  extern template wostream& operator<<(wostream&, _Setfill<wchar_t>);
534  extern template wostream& operator<<(wostream&, _Setiosflags);
535  extern template wostream& operator<<(wostream&, _Resetiosflags);
536  extern template wostream& operator<<(wostream&, _Setbase);
537  extern template wostream& operator<<(wostream&, _Setprecision);
538  extern template wostream& operator<<(wostream&, _Setw);
539  extern template wistream& operator>>(wistream&, _Setfill<wchar_t>);
540  extern template wistream& operator>>(wistream&, _Setiosflags);
541  extern template wistream& operator>>(wistream&, _Resetiosflags);
542  extern template wistream& operator>>(wistream&, _Setbase);
543  extern template wistream& operator>>(wistream&, _Setprecision);
544  extern template wistream& operator>>(wistream&, _Setw);
545 #endif
546 #endif
547 
548 _GLIBCXX_END_NAMESPACE_VERSION
549 } // namespace
550 
551 #pragma GCC diagnostic pop
552 #endif /* _GLIBCXX_IOMANIP */