cppdraft_translate/cppdraft/locale/moneypunct.md

[locale.moneypunct]

# 28 Text processing library [[text]](./#text)

## 28.3 Localization library [[localization]](localization#locale.moneypunct)

### 28.3.4 Standard locale categories [[locale.categories]](locale.categories#locale.moneypunct)

#### 28.3.4.7 The monetary category [[category.monetary]](category.monetary#locale.moneypunct)

#### 28.3.4.7.4 Class template moneypunct [locale.moneypunct]

#### [28.3.4.7.4.1](#general) General [[locale.moneypunct.general]](locale.moneypunct.general)

[🔗](#lib:moneypunct)

namespace std {class money_base {public:enum part { none, space, symbol, sign, value }; struct pattern { char field[4]; }; }; template<class charT, bool International = false>class moneypunct : public locale::facet, public money_base {public:using char_type = charT; using string_type = basic_string<charT>; explicit moneypunct(size_t refs = 0);

 charT decimal_point() const;
 charT thousands_sep() const;
 string grouping() const;
 string_type curr_symbol() const;
 string_type positive_sign() const;
 string_type negative_sign() const; int frac_digits() const;
 pattern pos_format() const;
 pattern neg_format() const; static locale::id id; static const bool intl = International; protected:~moneypunct(); virtual charT do_decimal_point() const; virtual charT do_thousands_sep() const; virtual string do_grouping() const; virtual string_type do_curr_symbol() const; virtual string_type do_positive_sign() const; virtual string_type do_negative_sign() const; virtual int do_frac_digits() const; virtual pattern do_pos_format() const; virtual pattern do_neg_format() const; };}

[1](#general-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L4465)

The moneypunct<> facet defines monetary formatting parameters
used by money_get<> and money_put<>[.](#general-1.sentence-1)

A monetary format is a sequence of four components,
specified by a pattern value p,
such that the part value static_cast<part>(p.field[i]) determines the ith component of the format[.](#general-1.sentence-2)[230](#footnote-230 "An array of char, rather than an array of part, is specified for pattern​::​field purely for efficiency.")

In the field member of a pattern object,
each value symbol, sign, value, and
either space or none appears exactly once[.](#general-1.sentence-3)

The value none, if present, is not first;
the value space, if present, is neither first nor last[.](#general-1.sentence-4)

[2](#general-2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L4484)

Where none or space appears,
whitespace is permitted in the format,
except where none appears at the end,
in which case no whitespace is permitted[.](#general-2.sentence-1)

The value space indicates that
at least one space is required at that position[.](#general-2.sentence-2)

Where symbol appears,
the sequence of characters returned by curr_symbol() is permitted, and
can be required[.](#general-2.sentence-3)

Where sign appears,
the first (if any) of the sequence of characters returned bypositive_sign() or negative_sign() (respectively as the monetary value is non-negative or negative) is required[.](#general-2.sentence-4)

Any remaining characters of the sign sequence are required after
all other format components[.](#general-2.sentence-5)

Where value appears, the absolute numeric monetary value is required[.](#general-2.sentence-6)

[3](#general-3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L4502)

The format of the numeric monetary value is a decimal number:

value :  
units fractionalopt  
decimal-point digits

fractional :  
decimal-point digitsopt

if frac_digits() returns a positive value, or

value :  
units

otherwise[.](#general-3.sentence-1)

The symbol *decimal-point* indicates the character returned by decimal_point()[.](#general-3.sentence-2)

The other symbols are defined as follows:

units :  
digits  
digits thousands-sep units

digits :  
adigit digitsopt

In the syntax specification,
the symbol *adigit* is any of the values ct.widen(c) for c in the range '0' through '9' (inclusive) andct is a reference of type const ctype<charT>& obtained as described in the definitions
of money_get<> and money_put<>[.](#general-3.sentence-4)

The symbol *thousands-sep* is the character returned by thousands_sep()[.](#general-3.sentence-5)

The space character used is the value ct.widen(' ')[.](#general-3.sentence-6)

Whitespace characters are those characters c for which ci.is(space, c) returns true[.](#general-3.sentence-7)

The number of digits required after the decimal point (if any)
is exactly the value returned by frac_digits()[.](#general-3.sentence-8)

[4](#general-4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L4548)

The placement of thousands-separator characters (if any)
is determined by the value returned by grouping(),
defined identically as the member numpunct<>​::​do_grouping()[.](#general-4.sentence-1)

[230)](#footnote-230)[230)](#footnoteref-230)

An array of char,
rather than an array of part,
is specified for pattern​::​field purely for efficiency[.](#footnote-230.sentence-1)

#### [28.3.4.7.4.2](#members) Members [[locale.moneypunct.members]](locale.moneypunct.members)

[🔗](#lib:moneypunct,decimal_point)

charT decimal_point() const;
charT thousands_sep() const;
string grouping() const;
string_type curr_symbol() const;
string_type positive_sign() const;
string_type negative_sign() const;int frac_digits() const;
pattern pos_format() const;
pattern neg_format() const;

[1](#members-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L4576)

Each of these functions *F* returns the result of calling the corresponding
virtual member functiondo_*F*()[.](#members-1.sentence-1)

#### [28.3.4.7.4.3](#virtuals) Virtual functions [[locale.moneypunct.virtuals]](locale.moneypunct.virtuals)

[🔗](#lib:moneypunct,do_decimal_point)

`charT do_decimal_point() const;
`

[1](#virtuals-1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L4590)

*Returns*: The radix separator to use
in case do_frac_digits() is greater than zero[.](#virtuals-1.sentence-1)[231](#footnote-231 "In common U.S. locales this is '.'.")

[🔗](#lib:moneypunct,do_thousands_sep)

`charT do_thousands_sep() const;
`

[2](#virtuals-2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L4605)

*Returns*: The digit group separator to use
in case do_grouping() specifies a digit grouping pattern[.](#virtuals-2.sentence-1)[232](#footnote-232 "In common U.S. locales this is ','.")

[🔗](#lib:moneypunct,do_grouping)

`string do_grouping() const;
`

[3](#virtuals-3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L4620)

*Returns*: A pattern defined identically as, but not necessarily equal to,
the result of numpunct<charT>​::​​do_grouping()[.](#virtuals-3.sentence-1)[233](#footnote-233 "To specify grouping by 3s, the value is &quot;\003&quot; not &quot;3&quot;.")

[🔗](#lib:moneypunct,do_curr_symbol)

`string_type do_curr_symbol() const;
`

[4](#virtuals-4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L4636)

*Returns*: A string to use as the currency identifier symbol[.](#virtuals-4.sentence-1)

[*Note [1](#virtuals-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[[bib]](bibliography#bib:iso4217 "Bibliography") followed by a space[.](#virtuals-4.sentence-2)

— *end note*]

[🔗](#lib:moneypunct,do_positive_sign)

`string_type do_positive_sign() const;
string_type do_negative_sign() const;
`

[5](#virtuals-5)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L4655)

*Returns*: do_positive_sign() returns the string to use to indicate a positive monetary value;[234](#footnote-234 "This is usually the empty string.")do_negative_sign() returns the string to use to indicate a negative value[.](#virtuals-5.sentence-1)

[🔗](#lib:moneypunct,do_frac_digits)

`int do_frac_digits() const;
`

[6](#virtuals-6)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L4672)

*Returns*: The number of digits after the decimal radix separator, if any[.](#virtuals-6.sentence-1)[235](#footnote-235 "In common U.S.&nbsp;locales, this is 2.")

[🔗](#lib:moneypunct,do_pos_format)

`pattern do_pos_format() const;
pattern do_neg_format() const;
`

[7](#virtuals-7)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L4688)

*Returns*: The specializations required in Table [92](locale.category#tab:locale.spec "Table 92: Required specializations") ([[locale.category]](locale.category "28.3.3.1.2.1 Type locale​::​category")), namely

- [(7.1)](#virtuals-7.1)

moneypunct<char>,

- [(7.2)](#virtuals-7.2)

moneypunct<wchar_t>,

- [(7.3)](#virtuals-7.3)

moneypunct<char, true>, and

- [(7.4)](#virtuals-7.4)

moneypunct<wchar_t, true>,

return an object of type pattern initialized to { symbol, sign, none, value }[.](#virtuals-7.sentence-1)[236](#footnote-236 "Note that the international symbol returned by do_­curr_­symbol() usually contains a space, itself; for example, &quot;USD &quot;.")

[231)](#footnote-231)[231)](#footnoteref-231)

In common U.S. locales this is '.'[.](#footnote-231.sentence-1)

[232)](#footnote-232)[232)](#footnoteref-232)

In common U.S. locales this is ','[.](#footnote-232.sentence-1)

[233)](#footnote-233)[233)](#footnoteref-233)

To specify grouping by 3s,
the value is "\003" *not* "3"[.](#footnote-233.sentence-1)

[234)](#footnote-234)[234)](#footnoteref-234)

This is usually the empty string[.](#footnote-234.sentence-1)

[235)](#footnote-235)[235)](#footnoteref-235)

In common U.S. locales, this is 2[.](#footnote-235.sentence-1)

[236)](#footnote-236)[236)](#footnoteref-236)

Note that the international symbol returned by do_curr_symbol() usually contains a space, itself;
for example, "USD "[.](#footnote-236.sentence-1)