From Jason Turner

[ostream.formatted]

C++11 → C++14 6.8 KB 65 lines
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Archived: C++11 | C++14
Markdown: C++11 | C++14
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  1. tmp/tmpi26wdj61/{from.md → to.md} +32 -24
tmp/tmpi26wdj61/{from.md → to.md} RENAMED
@@ -6,19 +6,28 @@ Each formatted output function begins execution by constructing an
6
  object of class `sentry`. If this object returns `true` when converted
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  to a value of type `bool`, the function endeavors to generate the
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  requested output. If the generation fails, then the formatted output
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  function does `setstate(ios_base::failbit)`, which might throw an
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  exception. If an exception is thrown during output, then `ios::badbit`
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- is turned on[^31] in `*this`’s error state. If
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  `(exceptions()&badbit) != 0` then the exception is rethrown. Whether or
13
  not an exception is thrown, the `sentry` object is destroyed before
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  leaving the formatted output function. If no exception is thrown, the
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  result of the formatted output function is `*this`.
16
 
17
- The descriptions of the individual formatted output operations describe
18
  how they perform output and do not mention the `sentry` object.
19
 
 
 
 
 
 
 
 
 
 
20
  ##### Arithmetic inserters <a id="ostream.inserters.arithmetic">[[ostream.inserters.arithmetic]]</a>
21
 
22
  ``` cpp
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  operator<<(bool val);
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  operator<<(short val);
@@ -90,11 +99,11 @@ performed the following code fragment:
90
 
91
  ``` cpp
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  bool failed = use_facet<
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  num_put<charT,ostreambuf_iterator<charT,traits> >
94
  >(getloc()).put(*this, *this, fill(),
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- static_cast<double>(va})).failed();
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  ```
97
 
98
  The first argument provides an object of the `ostreambuf_iterator<>`
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  class which is an iterator for class `basic_ostream<>`. It bypasses
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  `ostream`s and uses `streambuf`s directly. Class `locale` relies on
@@ -109,32 +118,32 @@ from which to obtain other facets. If `failed` is `true` then does
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110
  ##### `basic_ostream::operator<<` <a id="ostream.inserters">[[ostream.inserters]]</a>
111
 
112
  ``` cpp
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  basic_ostream<charT,traits>& operator<<
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- (basic_ostream<charT,traits>& (*pf)(basic_ostream<charT,traits>&))
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  ```
116
 
117
  *Effects:* None. Does not behave as a formatted output function (as
118
  described in  [[ostream.formatted.reqmts]]).
119
 
120
- *Returns:* `pf(*this)`.[^32]
121
 
122
  ``` cpp
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  basic_ostream<charT,traits>& operator<<
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- (basic_ios<charT,traits>& (*pf)(basic_ios<charT,traits>&))
125
  ```
126
 
127
  *Effects:* Calls `pf(*this)`. This inserter does not behave as a
128
  formatted output function (as described
129
  in  [[ostream.formatted.reqmts]]).
130
 
131
- *Returns:* `*this`.[^33]
132
 
133
  ``` cpp
134
  basic_ostream<charT,traits>& operator<<
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- (ios_base& (*pf)(ios_base&))
136
  ```
137
 
138
  *Effects:* Calls `pf(*this)`. This inserter does not behave as a
139
  formatted output function (as described
140
  in  [[ostream.formatted.reqmts]]).
@@ -170,11 +179,11 @@ caught exception is rethrown.
170
  ##### Character inserter function templates <a id="ostream.inserters.character">[[ostream.inserters.character]]</a>
171
 
172
  ``` cpp
173
  template<class charT, class traits>
174
  basic_ostream<charT,traits>& operator<<(basic_ostream<charT,traits>& out,
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- charT c};
176
  template<class charT, class traits>
177
  basic_ostream<charT,traits>& operator<<(basic_ostream<charT,traits>& out,
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  char c);
179
  // specialization
180
  template<class traits>
@@ -187,18 +196,17 @@ template<class traits>
187
  template<class traits>
188
  basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>& out,
189
  unsigned char c);
190
  ```
191
 
192
- *Effects:* Behaves like a formatted inserter (as described
193
- in  [[ostream.formatted.reqmts]]) of `out`. After a `sentry` object is
194
- constructed it inserts characters. In case `c` has type `char` and the
195
- character type of the stream is not `char`, then the character to be
196
- inserted is `out.widen(c)`; otherwise the character is `c`. Padding is
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- determined as described in  [[facet.num.put.virtuals]]. `width(0)` is
198
- called. The insertion character and any required padding are inserted
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- into `out`.
200
 
201
  *Returns:* `out`.
202
 
203
  ``` cpp
204
  template<class charT, class traits>
@@ -219,13 +227,14 @@ template<class traits>
219
  ```
220
 
221
  *Requires:* `s` shall not be a null pointer.
222
 
223
  *Effects:* Behaves like a formatted inserter (as described
224
- in  [[ostream.formatted.reqmts]]) of `out`. After a `sentry` object is
225
- constructed it inserts `n` characters starting at `s`, where `n` is the
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- number that would be computed as if by:
 
227
 
228
  - `traits::length(s)` for the overload where the first argument is of
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  type `basic_ostream<charT, traits>&` and the second is of type
230
  `const charT*`, and also for the overload where the first argument is
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  of type `basic_ostream<char, traits>&` and the second is of type
@@ -234,12 +243,11 @@ number that would be computed as if by:
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  argument is of type `basic_ostream<charT, traits>&` and the second is
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  of type `const char*`,
236
  - `traits::length(reinterpret_cast<const char*>(s))` for the other two
237
  overloads.
238
 
239
- Padding is determined as described in  [[facet.num.put.virtuals]]. The
240
- `n` characters starting at `s` are widened using
241
- `out.widen` ([[basic.ios.members]]). The widened characters and any
242
- required padding are inserted into `out`. Calls `width(0)`.
243
 
244
  *Returns:* `out`.
245
 
 
6
  object of class `sentry`. If this object returns `true` when converted
7
  to a value of type `bool`, the function endeavors to generate the
8
  requested output. If the generation fails, then the formatted output
9
  function does `setstate(ios_base::failbit)`, which might throw an
10
  exception. If an exception is thrown during output, then `ios::badbit`
11
+ is turned on[^32] in `*this`’s error state. If
12
  `(exceptions()&badbit) != 0` then the exception is rethrown. Whether or
13
  not an exception is thrown, the `sentry` object is destroyed before
14
  leaving the formatted output function. If no exception is thrown, the
15
  result of the formatted output function is `*this`.
16
 
17
+ The descriptions of the individual formatted output functions describe
18
  how they perform output and do not mention the `sentry` object.
19
 
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+ If a formatted output function of a stream `os` determines padding, it
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+ does so as follows. Given a `charT` character sequence `seq` where
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+ `charT` is the character type of the stream, if the length of `seq` is
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+ less than `os.width()`, then enough copies of `os.fill()` are added to
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+ this sequence as necessary to pad to a width of `os.width()` characters.
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+ If `(os.flags() & ios_base::adjustfield) == ios_base::left` is `true`,
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+ the fill characters are placed after the character sequence; otherwise,
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+ they are placed before the character sequence.
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+
29
  ##### Arithmetic inserters <a id="ostream.inserters.arithmetic">[[ostream.inserters.arithmetic]]</a>
30
 
31
  ``` cpp
32
  operator<<(bool val);
33
  operator<<(short val);
 
99
 
100
  ``` cpp
101
  bool failed = use_facet<
102
  num_put<charT,ostreambuf_iterator<charT,traits> >
103
  >(getloc()).put(*this, *this, fill(),
104
+ static_cast<double>(val)).failed();
105
  ```
106
 
107
  The first argument provides an object of the `ostreambuf_iterator<>`
108
  class which is an iterator for class `basic_ostream<>`. It bypasses
109
  `ostream`s and uses `streambuf`s directly. Class `locale` relies on
 
118
 
119
  ##### `basic_ostream::operator<<` <a id="ostream.inserters">[[ostream.inserters]]</a>
120
 
121
  ``` cpp
122
  basic_ostream<charT,traits>& operator<<
123
+ (basic_ostream<charT,traits>& (*pf)(basic_ostream<charT,traits>&));
124
  ```
125
 
126
  *Effects:* None. Does not behave as a formatted output function (as
127
  described in  [[ostream.formatted.reqmts]]).
128
 
129
+ *Returns:* `pf(*this)`.[^33]
130
 
131
  ``` cpp
132
  basic_ostream<charT,traits>& operator<<
133
+ (basic_ios<charT,traits>& (*pf)(basic_ios<charT,traits>&));
134
  ```
135
 
136
  *Effects:* Calls `pf(*this)`. This inserter does not behave as a
137
  formatted output function (as described
138
  in  [[ostream.formatted.reqmts]]).
139
 
140
+ *Returns:* `*this`.[^34]
141
 
142
  ``` cpp
143
  basic_ostream<charT,traits>& operator<<
144
+ (ios_base& (*pf)(ios_base&));
145
  ```
146
 
147
  *Effects:* Calls `pf(*this)`. This inserter does not behave as a
148
  formatted output function (as described
149
  in  [[ostream.formatted.reqmts]]).
 
179
  ##### Character inserter function templates <a id="ostream.inserters.character">[[ostream.inserters.character]]</a>
180
 
181
  ``` cpp
182
  template<class charT, class traits>
183
  basic_ostream<charT,traits>& operator<<(basic_ostream<charT,traits>& out,
184
+ charT c);
185
  template<class charT, class traits>
186
  basic_ostream<charT,traits>& operator<<(basic_ostream<charT,traits>& out,
187
  char c);
188
  // specialization
189
  template<class traits>
 
196
  template<class traits>
197
  basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>& out,
198
  unsigned char c);
199
  ```
200
 
201
+ *Effects:* Behaves as a formatted output function
202
+ (  [[ostream.formatted.reqmts]]) of `out`. Constructs a character
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+ sequence `seq`. If `c` has type `char` and the character type of the
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+ stream is not `char`, then `seq` consists of `out.widen(c)`; otherwise
205
+ `seq` consists of `c`. Determines padding for `seq` as described
206
+ in  [[ostream.formatted.reqmts]]. Inserts `seq` into `out`. Calls
207
+ `os.width(0)`.
 
208
 
209
  *Returns:* `out`.
210
 
211
  ``` cpp
212
  template<class charT, class traits>
 
227
  ```
228
 
229
  *Requires:* `s` shall not be a null pointer.
230
 
231
  *Effects:* Behaves like a formatted inserter (as described
232
+ in  [[ostream.formatted.reqmts]]) of `out`. Creates a character sequence
233
+ `seq` of `n` characters starting at `s`, each widened using
234
+ `out.widen()` ([[basic.ios.members]]), where `n` is the number that
235
+ would be computed as if by:
236
 
237
  - `traits::length(s)` for the overload where the first argument is of
238
  type `basic_ostream<charT, traits>&` and the second is of type
239
  `const charT*`, and also for the overload where the first argument is
240
  of type `basic_ostream<char, traits>&` and the second is of type
 
243
  argument is of type `basic_ostream<charT, traits>&` and the second is
244
  of type `const char*`,
245
  - `traits::length(reinterpret_cast<const char*>(s))` for the other two
246
  overloads.
247
 
248
+ Determines padding for `seq` as described
249
+ in  [[ostream.formatted.reqmts]]. Inserts `seq` into `out`. Calls
250
+ `width(0)`.
 
251
 
252
  *Returns:* `out`.
253