30 Localization library [localization]

30.4 Standard locale categories [locale.categories]

30.4.7 The monetary category [category.monetary]

30.4.7.4 Class template moneypunct [locale.moneypunct]

30.4.7.4.3 Virtual functions [locale.moneypunct.virtuals]

charT do_decimal_point() const;
Returns: The radix separator to use in case do_frac_digits() is greater than zero.259
charT do_thousands_sep() const;
Returns: The digit group separator to use in case do_grouping() specifies a digit grouping pattern.260
string do_grouping() const;
Returns: A pattern defined identically as, but not necessarily equal to, the result of numpunct<charT>​::​​do_grouping().261
string_type do_curr_symbol() const;
Returns: A string to use as the currency identifier symbol.
[Note 1: 
For specializations where the second template parameter is true, this is typically four characters long: a three-letter code as specified by ISO 4217 followed by a space.
— end note]
string_type do_positive_sign() const; string_type do_negative_sign() const;
Returns: do_positive_sign() returns the string to use to indicate a positive monetary value;262 do_negative_sign() returns the string to use to indicate a negative value.
int do_frac_digits() const;
Returns: The number of digits after the decimal radix separator, if any.263
pattern do_pos_format() const; pattern do_neg_format() const;
Returns: The specializations required in Table 105 ([locale.category]), namely
  • moneypunct<char>,
  • moneypunct<wchar_t>,
  • moneypunct<char, true>, and
  • moneypunct<wchar_t, true>,
return an object of type pattern initialized to { symbol, sign, none, value }.264
259)259)
In common U.S. locales this is '.'.
260)260)
In common U.S. locales this is ','.
261)261)
To specify grouping by 3s, the value is "\003" not "3".
262)262)
This is usually the empty string.
263)263)
In common U.S. locales, this is 2.
264)264)
Note that the international symbol returned by do_curr_symbol() usually contains a space, itself; for example, "USD ".