From Jason Turner

[facet.numpunct]

C++17 → C++20 4.3 KB 93 lines
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Archived: C++17 | C++20
Markdown: C++17 | C++20
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  1. tmp/tmpaebdmptw/{from.md → to.md} +59 -28
tmp/tmpaebdmptw/{from.md → to.md} RENAMED
@@ -31,43 +31,73 @@ namespace std {
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  }
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  ```
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  `numpunct<>`
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- specifies numeric punctuation. The specializations required in Table 
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- [[tab:localization.category.facets]] ([[locale.category]]), namely
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  `numpunct<{}wchar_t>` and `numpunct<char>`, provide classic `"C"`
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  numeric formats, i.e., they contain information equivalent to that
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  contained in the `"C"` locale or their wide character counterparts as if
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  obtained by a call to `widen`.
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- The syntax for number formats is as follows, where `digit` represents
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- the radix set specified by the `fmtflags` argument value, and
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- `thousands-sep` and `decimal-point` are the results of corresponding
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- `numpunct<charT>` members. Integer values have the format:
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-
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- ``` cpp
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- integer ::= [sign] units
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- sign ::= plusminus
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- plusminus ::= '+' | '-'
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- units ::= digits [thousands-sep units]
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- digits ::= digit [digits]
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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  ```
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  and floating-point values have:
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- ``` cpp
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- floatval ::= [sign] units [decimal-point [digits]] [e [sign] digits] |
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- [sign] decimal-point digits [e [sign] digits]
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- e ::= 'e' | 'E'
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  ```
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- where the number of digits between `thousands-sep`s is as specified by
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- `do_grouping()`. For parsing, if the `digits` portion contains no
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- thousands-separators, no grouping constraint is applied.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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- ##### `numpunct` members <a id="facet.numpunct.members">[[facet.numpunct.members]]</a>
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  ``` cpp
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  char_type decimal_point() const;
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  ```
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@@ -90,11 +120,11 @@ string_type truename() const;
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  string_type falsename() const;
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  ```
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  *Returns:* `do_truename()` or `do_falsename()`, respectively.
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- ##### `numpunct` virtual functions <a id="facet.numpunct.virtuals">[[facet.numpunct.virtuals]]</a>
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  ``` cpp
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  char_type do_decimal_point() const;
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  ```
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@@ -110,16 +140,16 @@ required specializations return `’,’` or `L’,’`.
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  ``` cpp
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  string do_grouping() const;
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  ```
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- *Returns:* A basic_string\<char\> `vec` used as a vector of integer
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- values, in which each element `vec[i]` represents the number of
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- digits[^13] in the group at position `i`, starting with position 0 as
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- the rightmost group. If `vec.size() <= i`, the number is the same as
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- group `(i - 1)`; if `(i < 0 || vec[i] <= 0 || vec[i] == CHAR_MAX)`, the
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- size of the digit group is unlimited.
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  The required specializations return the empty string, indicating no
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  grouping.
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  ``` cpp
@@ -144,10 +174,11 @@ namespace std {
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  using char_type = charT;
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  using string_type = basic_string<charT>;
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  explicit numpunct_byname(const char*, size_t refs = 0);
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  explicit numpunct_byname(const string&, size_t refs = 0);
 
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  protected:
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  ~numpunct_byname();
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  };
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  }
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  ```
 
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  }
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  ```
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  `numpunct<>`
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+ specifies numeric punctuation. The specializations required in
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+ [[locale.category.facets]] [[locale.category]], namely
38
  `numpunct<{}wchar_t>` and `numpunct<char>`, provide classic `"C"`
39
  numeric formats, i.e., they contain information equivalent to that
40
  contained in the `"C"` locale or their wide character counterparts as if
41
  obtained by a call to `widen`.
42
 
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+ The syntax for number formats is as follows, where represents the radix
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+ set specified by the `fmtflags` argument value, and and are the results
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+ of corresponding `numpunct<charT>` members. Integer values have the
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+ format:
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+
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+ ``` bnf
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+ intval:
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+ signₒₚₜ units
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+ ```
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+
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+ ``` bnf
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+ sign:
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+ '+'
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+ '-'
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+ ```
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+
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+ ``` bnf
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+ units:
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+ digits
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+ digits thousands-sep units
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+ ```
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+
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+ ``` bnf
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+ digits:
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+ digit digitsₒₚₜ
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  ```
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  and floating-point values have:
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+ ``` bnf
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+ floatval:
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+ signₒₚₜ units fractionalₒₚₜ exponentₒₚₜ
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+ signₒₚₜ decimal-point digits exponentₒₚₜ
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  ```
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+ ``` bnf
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+ fractional:
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+ decimal-point digitsₒₚₜ
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+ ```
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+
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+ ``` bnf
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+ exponent:
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+ e signₒₚₜ digits
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+ ```
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+
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+ ``` bnf
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+ e:
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+ 'e'
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+ 'E'
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+ ```
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+
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+ where the number of digits between is as specified by `do_grouping()`.
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+ For parsing, if the portion contains no thousands-separators, no
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+ grouping constraint is applied.
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+ ##### Members <a id="facet.numpunct.members">[[facet.numpunct.members]]</a>
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  ``` cpp
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  char_type decimal_point() const;
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  ```
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  string_type falsename() const;
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  ```
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  *Returns:* `do_truename()` or `do_falsename()`, respectively.
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+ ##### Virtual functions <a id="facet.numpunct.virtuals">[[facet.numpunct.virtuals]]</a>
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  ``` cpp
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  char_type do_decimal_point() const;
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  ```
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  ``` cpp
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  string do_grouping() const;
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  ```
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+ *Returns:* A `string` `vec` used as a vector of integer values, in which
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+ each element `vec[i]` represents the number of digits[^13] in the group
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+ at position `i`, starting with position 0 as the rightmost group. If
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+ `vec.size() <= i`, the number is the same as group `(i - 1)`; if
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+ `(i < 0 || vec[i] <= 0 || vec[i] == CHAR_MAX)`, the size of the digit
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+ group is unlimited.
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  The required specializations return the empty string, indicating no
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  grouping.
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  ``` cpp
 
174
  using char_type = charT;
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  using string_type = basic_string<charT>;
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  explicit numpunct_byname(const char*, size_t refs = 0);
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  explicit numpunct_byname(const string&, size_t refs = 0);
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+
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  protected:
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  ~numpunct_byname();
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  };
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  }
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  ```