From Jason Turner

[ios.types]

C++17 → C++20 9.7 KB 85 lines
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Archived: C++17 | C++20
Markdown: C++17 | C++20
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  1. tmp/tmpfd6k145q/{from.md → to.md} +36 -41
tmp/tmpfd6k145q/{from.md → to.md} RENAMED
@@ -1,8 +1,8 @@
1
  #### Types <a id="ios.types">[[ios.types]]</a>
2
 
3
- ##### Class `ios_base::failure` <a id="ios::failure">[[ios::failure]]</a>
4
 
5
  ``` cpp
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  namespace std {
7
  class ios_base::failure : public system_error {
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  public:
@@ -14,13 +14,13 @@ namespace std {
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15
  An implementation is permitted to define `ios_base::failure` as a
16
  synonym for a class with equivalent functionality to class
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  `ios_base::failure` shown in this subclause.
18
 
19
- [*Note 1*: When `ios_base::failure` is a synonym for another type it
20
- shall provide a nested type `failure`, to emulate the injected class
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- name. — *end note*]
22
 
23
  The class `failure` defines the base class for the types of all objects
24
  thrown as exceptions, by functions in the iostreams library, to report
25
  errors detected during stream buffer operations.
26
 
@@ -37,31 +37,28 @@ iostream_category())`. — *end note*]
37
 
38
  ``` cpp
39
  explicit failure(const string& msg, const error_code& ec = io_errc::stream);
40
  ```
41
 
42
- *Effects:* Constructs an object of class `failure` by constructing the
43
- base class with `msg` and `ec`.
44
 
45
  ``` cpp
46
  explicit failure(const char* msg, const error_code& ec = io_errc::stream);
47
  ```
48
 
49
- *Effects:* Constructs an object of class `failure` by constructing the
50
- base class with `msg` and `ec`.
51
 
52
- ##### Type `ios_base::fmtflags` <a id="ios::fmtflags">[[ios::fmtflags]]</a>
53
 
54
  ``` cpp
55
  using fmtflags = T1;
56
  ```
57
 
58
- The type `fmtflags` is a bitmask type ([[bitmask.types]]). Setting its
59
- elements has the effects indicated in
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- Table  [[tab:iostreams.fmtflags.effects]].
61
 
62
- **Table: `fmtflags` effects** <a id="tab:iostreams.fmtflags.effects">[tab:iostreams.fmtflags.effects]</a>
63
 
64
  | Element | Effect(s) if set |
65
  | ------------ | --------------------------------------------------------------------------------------------------------------------------------------- |
66
  | `boolalpha` | insert and extract `bool` type in alphabetic format |
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  | `dec` | converts integer input or generates integer output in decimal base |
@@ -79,31 +76,31 @@ Table  [[tab:iostreams.fmtflags.effects]].
79
  | `unitbuf` | flushes output after each output operation |
80
  | `uppercase` | replaces certain lowercase letters with their uppercase equivalents in generated output |
81
 
82
 
83
  Type `fmtflags` also defines the constants indicated in
84
- Table  [[tab:iostreams.fmtflags.constants]].
85
 
86
- **Table: `fmtflags` constants** <a id="tab:iostreams.fmtflags.constants">[tab:iostreams.fmtflags.constants]</a>
87
 
88
  | Constant | Allowable values |
89
  | ------------- | ------------------------- |
90
  | `adjustfield` | `left | right | internal` |
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  | `basefield` | `dec | oct | hex` |
92
  | `floatfield` | `scientific | fixed` |
93
 
94
 
95
- ##### Type `ios_base::iostate` <a id="ios::iostate">[[ios::iostate]]</a>
96
 
97
  ``` cpp
98
  using iostate = T2;
99
  ```
100
 
101
- The type `iostate` is a bitmask type ([[bitmask.types]]) that contains
102
- the elements indicated in Table  [[tab:iostreams.iostate.effects]].
103
 
104
- **Table: `iostate` effects** <a id="tab:iostreams.iostate.effects">[tab:iostreams.iostate.effects]</a>
105
 
106
  | Element | Effect(s) if set |
107
  | --------- | ------------------------------------------------------------------------------------------------------------------------------------------------ |
108
  | `badbit` | indicates a loss of integrity in an input or output sequence (such as an irrecoverable read error from a file); |
109
  | `eofbit` | indicates that an input operation reached the end of an input sequence; |
@@ -112,20 +109,20 @@ the elements indicated in Table  [[tab:iostreams.iostate.effects]].
112
 
113
  Type `iostate` also defines the constant:
114
 
115
  - `goodbit`, the value zero.
116
 
117
- ##### Type `ios_base::openmode` <a id="ios::openmode">[[ios::openmode]]</a>
118
 
119
  ``` cpp
120
  using openmode = T3;
121
  ```
122
 
123
- The type `openmode` is a bitmask type ([[bitmask.types]]). It contains
124
- the elements indicated in Table  [[tab:iostreams.openmode.effects]].
125
 
126
- **Table: `openmode` effects** <a id="tab:iostreams.openmode.effects">[tab:iostreams.openmode.effects]</a>
127
 
128
  | Element | Effect(s) if set |
129
  | -------- | ----------------------------------------------------------------- |
130
  | `app` | seek to end before each write |
131
  | `ate` | open and seek to end immediately after opening |
@@ -133,67 +130,65 @@ the elements indicated in Table  [[tab:iostreams.openmode.effects]].
133
  | `in` | open for input |
134
  | `out` | open for output |
135
  | `trunc` | truncate an existing stream when opening |
136
 
137
 
138
- ##### Type `ios_base::seekdir` <a id="ios::seekdir">[[ios::seekdir]]</a>
139
 
140
  ``` cpp
141
  using seekdir = T4;
142
  ```
143
 
144
- The type `seekdir` is an enumerated type ([[enumerated.types]]) that
145
- contains the elements indicated in
146
- Table  [[tab:iostreams.seekdir.effects]].
147
 
148
- **Table: `seekdir` effects** <a id="tab:iostreams.seekdir.effects">[tab:iostreams.seekdir.effects]</a>
149
 
150
  | Element | Meaning |
151
  | ------- | --------------------------------------------------------------------------------------- |
152
  | `beg` | request a seek (for subsequent input or output) relative to the beginning of the stream |
153
  | `cur` | request a seek relative to the current position within the sequence |
154
  | `end` | request a seek relative to the current end of the sequence |
155
 
156
 
157
- ##### Class `ios_base::Init` <a id="ios::Init">[[ios::Init]]</a>
158
 
159
  ``` cpp
160
  namespace std {
161
  class ios_base::Init {
162
  public:
163
  Init();
 
164
  ~Init();
 
165
  private:
166
  static int init_cnt; // exposition only
167
  };
168
  }
169
  ```
170
 
171
  The class `Init` describes an object whose construction ensures the
172
- construction of the eight objects declared in `<iostream>` (
173
- [[iostream.objects]]) that associate file stream buffers with the
174
- standard C streams provided for by the functions declared in
175
- `<cstdio>` ([[cstdio.syn]]).
176
 
177
  For the sake of exposition, the maintained data is presented here as:
178
 
179
  - `static int init_cnt`, counts the number of constructor and destructor
180
  calls for class `Init`, initialized to zero.
181
 
182
  ``` cpp
183
  Init();
184
  ```
185
 
186
- *Effects:* Constructs an object of class `Init`. Constructs and
187
- initializes the objects `cin`, `cout`, `cerr`, `clog`, `wcin`, `wcout`,
188
- `wcerr`, and `wclog` if they have not already been constructed and
189
- initialized.
190
 
191
  ``` cpp
192
  ~Init();
193
  ```
194
 
195
- *Effects:* Destroys an object of class `Init`. If there are no other
196
- instances of the class still in existence, calls `cout.flush()`,
197
- `cerr.flush()`, `clog.flush()`, `wcout.flush()`, `wcerr.flush()`,
198
- `wclog.flush()`.
199
 
 
1
  #### Types <a id="ios.types">[[ios.types]]</a>
2
 
3
+ ##### Class `ios_base::failure` <a id="ios.failure">[[ios.failure]]</a>
4
 
5
  ``` cpp
6
  namespace std {
7
  class ios_base::failure : public system_error {
8
  public:
 
14
 
15
  An implementation is permitted to define `ios_base::failure` as a
16
  synonym for a class with equivalent functionality to class
17
  `ios_base::failure` shown in this subclause.
18
 
19
+ [*Note 1*: When `ios_base::failure` is a synonym for another type, that
20
+ type is required to provide a nested type `failure` to emulate the
21
+ injected-class-name. — *end note*]
22
 
23
  The class `failure` defines the base class for the types of all objects
24
  thrown as exceptions, by functions in the iostreams library, to report
25
  errors detected during stream buffer operations.
26
 
 
37
 
38
  ``` cpp
39
  explicit failure(const string& msg, const error_code& ec = io_errc::stream);
40
  ```
41
 
42
+ *Effects:* Constructs the base class with `msg` and `ec`.
 
43
 
44
  ``` cpp
45
  explicit failure(const char* msg, const error_code& ec = io_errc::stream);
46
  ```
47
 
48
+ *Effects:* Constructs the base class with `msg` and `ec`.
 
49
 
50
+ ##### Type `ios_base::fmtflags` <a id="ios.fmtflags">[[ios.fmtflags]]</a>
51
 
52
  ``` cpp
53
  using fmtflags = T1;
54
  ```
55
 
56
+ The type `fmtflags` is a bitmask type [[bitmask.types]]. Setting its
57
+ elements has the effects indicated in [[ios.fmtflags]].
 
58
 
59
+ **Table: `fmtflags` effects** <a id="ios.fmtflags">[ios.fmtflags]</a>
60
 
61
  | Element | Effect(s) if set |
62
  | ------------ | --------------------------------------------------------------------------------------------------------------------------------------- |
63
  | `boolalpha` | insert and extract `bool` type in alphabetic format |
64
  | `dec` | converts integer input or generates integer output in decimal base |
 
76
  | `unitbuf` | flushes output after each output operation |
77
  | `uppercase` | replaces certain lowercase letters with their uppercase equivalents in generated output |
78
 
79
 
80
  Type `fmtflags` also defines the constants indicated in
81
+ [[ios.fmtflags.const]].
82
 
83
+ **Table: `fmtflags` constants** <a id="ios.fmtflags.const">[ios.fmtflags.const]</a>
84
 
85
  | Constant | Allowable values |
86
  | ------------- | ------------------------- |
87
  | `adjustfield` | `left | right | internal` |
88
  | `basefield` | `dec | oct | hex` |
89
  | `floatfield` | `scientific | fixed` |
90
 
91
 
92
+ ##### Type `ios_base::iostate` <a id="ios.iostate">[[ios.iostate]]</a>
93
 
94
  ``` cpp
95
  using iostate = T2;
96
  ```
97
 
98
+ The type `iostate` is a bitmask type [[bitmask.types]] that contains the
99
+ elements indicated in [[ios.iostate]].
100
 
101
+ **Table: `iostate` effects** <a id="ios.iostate">[ios.iostate]</a>
102
 
103
  | Element | Effect(s) if set |
104
  | --------- | ------------------------------------------------------------------------------------------------------------------------------------------------ |
105
  | `badbit` | indicates a loss of integrity in an input or output sequence (such as an irrecoverable read error from a file); |
106
  | `eofbit` | indicates that an input operation reached the end of an input sequence; |
 
109
 
110
  Type `iostate` also defines the constant:
111
 
112
  - `goodbit`, the value zero.
113
 
114
+ ##### Type `ios_base::openmode` <a id="ios.openmode">[[ios.openmode]]</a>
115
 
116
  ``` cpp
117
  using openmode = T3;
118
  ```
119
 
120
+ The type `openmode` is a bitmask type [[bitmask.types]]. It contains the
121
+ elements indicated in [[ios.openmode]].
122
 
123
+ **Table: `openmode` effects** <a id="ios.openmode">[ios.openmode]</a>
124
 
125
  | Element | Effect(s) if set |
126
  | -------- | ----------------------------------------------------------------- |
127
  | `app` | seek to end before each write |
128
  | `ate` | open and seek to end immediately after opening |
 
130
  | `in` | open for input |
131
  | `out` | open for output |
132
  | `trunc` | truncate an existing stream when opening |
133
 
134
 
135
+ ##### Type `ios_base::seekdir` <a id="ios.seekdir">[[ios.seekdir]]</a>
136
 
137
  ``` cpp
138
  using seekdir = T4;
139
  ```
140
 
141
+ The type `seekdir` is an enumerated type [[enumerated.types]] that
142
+ contains the elements indicated in [[ios.seekdir]].
 
143
 
144
+ **Table: `seekdir` effects** <a id="ios.seekdir">[ios.seekdir]</a>
145
 
146
  | Element | Meaning |
147
  | ------- | --------------------------------------------------------------------------------------- |
148
  | `beg` | request a seek (for subsequent input or output) relative to the beginning of the stream |
149
  | `cur` | request a seek relative to the current position within the sequence |
150
  | `end` | request a seek relative to the current end of the sequence |
151
 
152
 
153
+ ##### Class `ios_base::Init` <a id="ios.init">[[ios.init]]</a>
154
 
155
  ``` cpp
156
  namespace std {
157
  class ios_base::Init {
158
  public:
159
  Init();
160
+ Init(const Init&) = default;
161
  ~Init();
162
+ Init& operator=(const Init&) = default;
163
  private:
164
  static int init_cnt; // exposition only
165
  };
166
  }
167
  ```
168
 
169
  The class `Init` describes an object whose construction ensures the
170
+ construction of the eight objects declared in `<iostream>`
171
+ [[iostream.objects]] that associate file stream buffers with the
172
+ standard C streams provided for by the functions declared in `<cstdio>`.
 
173
 
174
  For the sake of exposition, the maintained data is presented here as:
175
 
176
  - `static int init_cnt`, counts the number of constructor and destructor
177
  calls for class `Init`, initialized to zero.
178
 
179
  ``` cpp
180
  Init();
181
  ```
182
 
183
+ *Effects:* Constructs and initializes the objects `cin`, `cout`, `cerr`,
184
+ `clog`, `wcin`, `wcout`, `wcerr`, and `wclog` if they have not already
185
+ been constructed and initialized.
 
186
 
187
  ``` cpp
188
  ~Init();
189
  ```
190
 
191
+ *Effects:* If there are no other instances of the class still in
192
+ existence, calls `cout.flush()`, `cerr.flush()`, `clog.flush()`,
193
+ `wcout.flush()`, `wcerr.flush()`, `wclog.flush()`.
 
194