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;
};
}

The
moneypunct<>
facet defines monetary formatting parameters used by
money_get<>
and
money_put<>.

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
component of the format280
In the
field
member of a
pattern
object, each value
symbol,
sign,
value,
and either
space
or
none
appears exactly once.

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.

The value
space
indicates that at least one space is required at that position.

Where
symbol
appears, the sequence of characters returned by
curr_symbol()
is permitted, and can be required.

Where
sign
appears, the first (if any) of the sequence of characters returned by
positive_sign()
or
negative_sign()
(respectively as the monetary value is non-negative or negative) is required.

Any remaining characters of the sign sequence are required after all
other format components.

Where
value
appears, the absolute numeric monetary value is required.

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

units fractional

decimal-point digits
*fractional*:

decimal-point digits
if frac_digits() returns a positive value, or
*value*:

units
otherwise.

units fractional

decimal-point digits

decimal-point digits

units

The other symbols are defined as follows:
*units*:

digits

digits thousands-sep units

digits

digits thousands-sep units

adigit digits

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

The space character used is the value ct.widen(' ').

The number of digits required after the decimal point (if any)
is exactly the value returned by frac_digits().

The placement of thousands-separator characters (if any)
is determined by the value returned by
grouping(),
defined identically as the member
numpunct<>::do_grouping().