[locale.numpunct.general] (original) (raw)

28 Text processing library [text]

28.3 Localization library [localization]

28.3.4 Standard locale categories [locale.categories]

28.3.4.4.1 Class template numpunct [locale.numpunct]

28.3.4.4.1.1 General [locale.numpunct.general]

namespace std { template<class charT> class numpunct : public locale::facet { public: using char_type = charT;using string_type = basic_string<charT>;explicit numpunct(size_t refs = 0); char_type decimal_point() const; char_type thousands_sep() const; string grouping() const; string_type truename() const; string_type falsename() const;static locale::id id;protected: ~numpunct(); virtual char_type do_decimal_point() const;virtual char_type do_thousands_sep() const;virtual string do_grouping() const;virtual string_type do_truename() const; virtual string_type do_falsename() const; };}

numpunct<> specifies numeric punctuation.

The specializations required in Table 89 ([locale.category]), namely numpunct<wchar_t> and numpunct<char>, provide classic "C" numeric formats, i.e., they contain information equivalent to that contained in the "C" locale or their wide character counterparts as if obtained by a call to widen.

The syntax for number formats is as follows, where digit represents the radix set specified by the fmtflags argument value, and_thousands-sep_ and _decimal-point_are the results of corresponding numpunct<charT> members.

Integer values have the format:

intval :
sign units

units :
digits
digits thousands-sep units

digits :
digit digits

and floating-point values have:

floatval :
sign units fractional exponent
sign decimal-point digits exponent

fractional :
decimal-point digits

exponent :
e sign digits

e :
e
E

where the number of digits between thousands-sep _s_is as specified by do_grouping().