From Jason Turner

[charconv]

C++20 → C++23 7.9 KB 79 lines
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Archived: C++20 | C++23
Markdown: C++20 | C++23
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  1. tmp/tmphnk2ya97/{from.md → to.md} +22 -47
tmp/tmphnk2ya97/{from.md → to.md} RENAMED
@@ -1,9 +1,17 @@
1
  ## Primitive numeric conversions <a id="charconv">[[charconv]]</a>
2
 
3
  ### Header `<charconv>` synopsis <a id="charconv.syn">[[charconv.syn]]</a>
4
 
 
 
 
 
 
 
 
 
5
  ``` cpp
6
  %
7
  %
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  {chars_format{chars_format{chars_format{chars_formatnamespace std {
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  // floating-point format for primitive numerical conversion
@@ -22,26 +30,16 @@
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  char* ptr;
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  errc ec;
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  friend bool operator==(const to_chars_result&, const to_chars_result&) = default;
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  };
26
 
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- to_chars_result to_chars(char* first, char* last, see below value, int base = 10);
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  to_chars_result to_chars(char* first, char* last, bool value, int base = 10) = delete;
29
 
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- to_chars_result to_chars(char* first, char* last, float value);
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- to_chars_result to_chars(char* first, char* last, double value);
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- to_chars_result to_chars(char* first, char* last, long double value);
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-
34
- to_chars_result to_chars(char* first, char* last, float value, chars_format fmt);
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- to_chars_result to_chars(char* first, char* last, double value, chars_format fmt);
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- to_chars_result to_chars(char* first, char* last, long double value, chars_format fmt);
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-
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- to_chars_result to_chars(char* first, char* last, float value,
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- chars_format fmt, int precision);
40
- to_chars_result to_chars(char* first, char* last, double value,
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- chars_format fmt, int precision);
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- to_chars_result to_chars(char* first, char* last, long double value,
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  chars_format fmt, int precision);
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  %
45
  %
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  {from_chars_result{from_chars_result}
47
 
@@ -50,18 +48,14 @@
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  const char* ptr;
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  errc ec;
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  friend bool operator==(const from_chars_result&, const from_chars_result&) = default;
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  };
54
 
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- from_chars_result from_chars(const char* first, const char* last,
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- see below& value, int base = 10);
57
 
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- from_chars_result from_chars(const char* first, const char* last, float& value,
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- chars_format fmt = chars_format::general);
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- from_chars_result from_chars(const char* first, const char* last, double& value,
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- chars_format fmt = chars_format::general);
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- from_chars_result from_chars(const char* first, const char* last, long double& value,
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  chars_format fmt = chars_format::general);
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  }
65
  ```
66
 
67
  The type `chars_format` is a bitmask type [[bitmask.types]] with
@@ -103,11 +97,11 @@ specifier for `printf` as follows: The conversion specifier is `f` if
103
  `chars_format::scientific`, `a` (without leading `"0x"` in the result)
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  if `fmt` is `chars_format::hex`, and `g` if `fmt` is
105
  `chars_format::general`.
106
 
107
  ``` cpp
108
- to_chars_result to_chars(char* first, char* last, see below value, int base = 10);
109
  ```
110
 
111
  *Preconditions:* `base` has a value between 2 and 36 (inclusive).
112
 
113
  *Effects:* The value of `value` is converted to a string of digits in
@@ -115,30 +109,23 @@ the given base (with no redundant leading zeroes). Digits in the range
115
  10..35 (inclusive) are represented as lowercase characters `a`..`z`. If
116
  `value` is less than zero, the representation starts with `’-’`.
117
 
118
  *Throws:* Nothing.
119
 
120
- *Remarks:* The implementation shall provide overloads for all signed and
121
- unsigned integer types and `char` as the type of the parameter `value`.
122
-
123
  ``` cpp
124
- to_chars_result to_chars(char* first, char* last, float value);
125
- to_chars_result to_chars(char* first, char* last, double value);
126
- to_chars_result to_chars(char* first, char* last, long double value);
127
  ```
128
 
129
  *Effects:* `value` is converted to a string in the style of `printf` in
130
  the `"C"` locale. The conversion specifier is `f` or `e`, chosen
131
  according to the requirement for a shortest representation (see above);
132
  a tie is resolved in favor of `f`.
133
 
134
  *Throws:* Nothing.
135
 
136
  ``` cpp
137
- to_chars_result to_chars(char* first, char* last, float value, chars_format fmt);
138
- to_chars_result to_chars(char* first, char* last, double value, chars_format fmt);
139
- to_chars_result to_chars(char* first, char* last, long double value, chars_format fmt);
140
  ```
141
 
142
  *Preconditions:* `fmt` has the value of one of the enumerators of
143
  `chars_format`.
144
 
@@ -146,15 +133,11 @@ to_chars_result to_chars(char* first, char* last, long double value, chars_forma
146
  the `"C"` locale.
147
 
148
  *Throws:* Nothing.
149
 
150
  ``` cpp
151
- to_chars_result to_chars(char* first, char* last, float value,
152
- chars_format fmt, int precision);
153
- to_chars_result to_chars(char* first, char* last, double value,
154
- chars_format fmt, int precision);
155
- to_chars_result to_chars(char* first, char* last, long double value,
156
  chars_format fmt, int precision);
157
  ```
158
 
159
  *Preconditions:* `fmt` has the value of one of the enumerators of
160
  `chars_format`.
@@ -187,12 +170,12 @@ unmodified and the member `ec` of the return value is equal to
187
  `errc::result_out_of_range`. Otherwise, `value` is set to the parsed
188
  value, after rounding according to `round_to_nearest` [[round.style]],
189
  and the member `ec` is value-initialized.
190
 
191
  ``` cpp
192
- from_chars_result from_chars(const char* first, const char* last,
193
- see below& value, int base = 10);
194
  ```
195
 
196
  *Preconditions:* `base` has a value between 2 and 36 (inclusive).
197
 
198
  *Effects:* The pattern is the expected form of the subject sequence in
@@ -201,20 +184,12 @@ except that no `"0x"` or `"0X"` prefix shall appear if the value of
201
  `base` is 16, and except that `’-’` is the only sign that may appear,
202
  and only if `value` has a signed type.
203
 
204
  *Throws:* Nothing.
205
 
206
- *Remarks:* The implementation shall provide overloads for all signed and
207
- unsigned integer types and `char` as the referenced type of the
208
- parameter `value`.
209
-
210
  ``` cpp
211
- from_chars_result from_chars(const char* first, const char* last, float& value,
212
- chars_format fmt = chars_format::general);
213
- from_chars_result from_chars(const char* first, const char* last, double& value,
214
- chars_format fmt = chars_format::general);
215
- from_chars_result from_chars(const char* first, const char* last, long double& value,
216
  chars_format fmt = chars_format::general);
217
  ```
218
 
219
  *Preconditions:* `fmt` has the value of one of the enumerators of
220
  `chars_format`.
 
1
  ## Primitive numeric conversions <a id="charconv">[[charconv]]</a>
2
 
3
  ### Header `<charconv>` synopsis <a id="charconv.syn">[[charconv.syn]]</a>
4
 
5
+ When a function is specified with a type placeholder of `integer-type`,
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+ the implementation provides overloads for all cv-unqualified signed and
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+ unsigned integer types and `char` in lieu of `integer-type`. When a
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+ function is specified with a type placeholder of `floating-point-type`,
9
+ the implementation provides overloads for all cv-unqualified
10
+ floating-point types [[basic.fundamental]] in lieu of
11
+ `floating-point-type`.
12
+
13
  ``` cpp
14
  %
15
  %
16
  {chars_format{chars_format{chars_format{chars_formatnamespace std {
17
  // floating-point format for primitive numerical conversion
 
30
  char* ptr;
31
  errc ec;
32
  friend bool operator==(const to_chars_result&, const to_chars_result&) = default;
33
  };
34
 
35
+ constexpr to_chars_result to_chars(char* first, char* last, integer-type value, int base = 10);
36
  to_chars_result to_chars(char* first, char* last, bool value, int base = 10) = delete;
37
 
38
+ to_chars_result to_chars(char* first, char* last, floating-point-type value);
39
+ to_chars_result to_chars(char* first, char* last, floating-point-type value, chars_format fmt);
40
+ to_chars_result to_chars(char* first, char* last, floating-point-type value,
 
 
 
 
 
 
 
 
 
 
41
  chars_format fmt, int precision);
42
  %
43
  %
44
  {from_chars_result{from_chars_result}
45
 
 
48
  const char* ptr;
49
  errc ec;
50
  friend bool operator==(const from_chars_result&, const from_chars_result&) = default;
51
  };
52
 
53
+ constexpr from_chars_result from_chars(const char* first, const char* last,
54
+ integer-type& value, int base = 10);
55
 
56
+ from_chars_result from_chars(const char* first, const char* last, floating-point-type& value,
 
 
 
 
57
  chars_format fmt = chars_format::general);
58
  }
59
  ```
60
 
61
  The type `chars_format` is a bitmask type [[bitmask.types]] with
 
97
  `chars_format::scientific`, `a` (without leading `"0x"` in the result)
98
  if `fmt` is `chars_format::hex`, and `g` if `fmt` is
99
  `chars_format::general`.
100
 
101
  ``` cpp
102
+ constexpr to_chars_result to_chars(char* first, char* last, integer-type value, int base = 10);
103
  ```
104
 
105
  *Preconditions:* `base` has a value between 2 and 36 (inclusive).
106
 
107
  *Effects:* The value of `value` is converted to a string of digits in
 
109
  10..35 (inclusive) are represented as lowercase characters `a`..`z`. If
110
  `value` is less than zero, the representation starts with `’-’`.
111
 
112
  *Throws:* Nothing.
113
 
 
 
 
114
  ``` cpp
115
+ to_chars_result to_chars(char* first, char* last, floating-point-type value);
 
 
116
  ```
117
 
118
  *Effects:* `value` is converted to a string in the style of `printf` in
119
  the `"C"` locale. The conversion specifier is `f` or `e`, chosen
120
  according to the requirement for a shortest representation (see above);
121
  a tie is resolved in favor of `f`.
122
 
123
  *Throws:* Nothing.
124
 
125
  ``` cpp
126
+ to_chars_result to_chars(char* first, char* last, floating-point-type value, chars_format fmt);
 
 
127
  ```
128
 
129
  *Preconditions:* `fmt` has the value of one of the enumerators of
130
  `chars_format`.
131
 
 
133
  the `"C"` locale.
134
 
135
  *Throws:* Nothing.
136
 
137
  ``` cpp
138
+ to_chars_result to_chars(char* first, char* last, floating-point-type value,
 
 
 
 
139
  chars_format fmt, int precision);
140
  ```
141
 
142
  *Preconditions:* `fmt` has the value of one of the enumerators of
143
  `chars_format`.
 
170
  `errc::result_out_of_range`. Otherwise, `value` is set to the parsed
171
  value, after rounding according to `round_to_nearest` [[round.style]],
172
  and the member `ec` is value-initialized.
173
 
174
  ``` cpp
175
+ constexpr from_chars_result from_chars(const char* first, const char* last,
176
+ integer-type& value, int base = 10);
177
  ```
178
 
179
  *Preconditions:* `base` has a value between 2 and 36 (inclusive).
180
 
181
  *Effects:* The pattern is the expected form of the subject sequence in
 
184
  `base` is 16, and except that `’-’` is the only sign that may appear,
185
  and only if `value` has a signed type.
186
 
187
  *Throws:* Nothing.
188
 
 
 
 
 
189
  ``` cpp
190
+ from_chars_result from_chars(const char* first, const char* last, floating-point-type& value,
 
 
 
 
191
  chars_format fmt = chars_format::general);
192
  ```
193
 
194
  *Preconditions:* `fmt` has the value of one of the enumerators of
195
  `chars_format`.