Standard C++ Library
Copyright 1998, Rogue Wave Software, Inc.
NAME
moneypunct, moneypunct_byname
- Monetary punctuation facets.
SYNOPSIS
#include <locale>
class money_base;
template <class charT, bool International = false>
class moneypunct;
DESCRIPTION
The moneypunct_facets include formatting specifications and
punctuation character for monetary values. The moneypunct
facet is used with the "C" locale, while
the_moneypunct_byname facet is used with named locales.
The facet is used by money_put_for outputting formatted
representations of monetary values and by_money_get for
reading these strings back in.
money_base includes a structure, pattern, that specifies the
order of syntactic elements in a monetary value and enumera-
tion values representing those elements. The pattern struct
includes a simple array of characters, field. Each index in
field is taken up by an enumeration value indicating the
location of a syntactic element. The enumeration values are
described below:
FORMAT FLAG MEANING
none No grouping separator
space Use space for grouping separator
symbol Currency symbol
sign Sign of monetary value
value The monetary value itself
The do_pos_format and do_neg_format member functions of
moneypunct both return the pattern type. See the description
of these functions for further elaboration.
INTERFACE
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:
typedef charT char_type;
typedef basic_string<charT> string_type;
explicit moneypunct(size_t = 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
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;
};
template <class charT, bool Intl = false>
class moneypunct_byname : public moneypunct<charT, Intl> {
public:
explicit moneypunct_byname(const char*, size_t = 0);
protected:
~moneypunct_byname(); // virtual
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;
};
TYPES
char_type
Type of character the facet is instantiated on.
string_type
Type of character string returned by member functions.
CONSTRUCTORS
explicit moneypunct(size_t refs = 0)
Constructs a moneypunct facet. If the refs argument is 0,
then destruction of the object is delegated to the
locale, or locales, containing it. This allows the user
to ignore lifetime management issues. On the other hand,
if refs is 1, then the object must be explicitly deleted;
the locale does not do so. In this case, the object can
be maintained across the lifetime of multiple locales.
explicit moneypunct_byname(const char* name,
size_t refs = 0);
Constructs a moneypunct_byname facet. Uses the named
locale specified by the name argument. The refs argument
serves the same purpose as it does for the moneypunct
constructor.
DESTRUCTORS
~moneypunct(); // virtual and protected
Destroys the facet.
STATIC MEMBERS
static locale::id id;
Unique identifier for this type of facet.
static const bool intl = Intl;
true for international representation, false otherwise.
PUBLIC MEMBER FUNCTIONS
The public members of the moneypunct and_moneypunct_byname
facets include an interface to protected members. Each pub-
lic member xxx has a corresponding virtual protected member
do_xxx. All work is delegated to these protected members.
For instance, the long version of the public decimal_point
function simply calls its protected cousin do_decimal_point.
string_type curr_symbol() const;
charT decimal_point() const;
int frac_digits() const;
string grouping() const;
pattern neg_format() const;
string_type negative_sign() const;
pattern pos_format() const;
string_type positive_sign() const;
charT thousands_sep() const;
Each public member function xxx simply calls the
corresponding protected do_xxx function.
PROTECTED MEMBER FUNCTIONS
virtual string_type
do_curr_symbol() const;
Returns a string to use as the currency symbol.
virtual charT
do_decimal_point() const;
Returns the radix separator to use if fractional digits
are allowed (see do_frac_digits).
virtual int
do_frac_digits() const;
Returns the number of digits in the fractional part of
the monetary representation.
virtual string
do_grouping() const;
Returns a string in which each character is used as an
integer value to represent the number of digits in a par-
ticular grouping, starting with the rightmost group. A
group is simply the digits between adjacent thousands'
separators. Each group at a position larger than the size
of the string gets the same value as the last element in
the string. If a value is less than or equal to zero, or
equal to CHAR_MAX, then the size of that group is unlim-
ited. moneypunct returns an empty string, indicating no
grouping.
virtual string_type
do_negative_sign() const;
A string to use as the negative sign. The first character
of this string is placed in the position indicated by the
format pattern (see do_neg_format); the rest of the char-
acters, if any, are placed after all other parts of the
monetary value.
virtual pattern
do_neg_format() const;
virtual pattern
do_pos_format() const;
Returns a pattern object specifying the location of the
various syntactic elements in a monetary representation.
The enumeration values symbol, sign, and value appear
exactly once in this pattern, with the remaining location
taken by either none or space. none never occupies the
first position in the pattern and space never occupies
the first or the last position. Beyond these restric-
tions, elements may appear in any order. moneypunct
returns {symbol, sign, none, value}.
virtual string_type
do_positive_sign() const;
A string to use as the positive sign. The first character
of this string is placed in the position indicated by the
format pattern (see do_pos_format); the rest of the char-
acters, if any, are placed after all other parts of the
monetary value.
virtual charT
do_thousands_sep() const;
Returns the grouping separator if grouping is allowed
(see do_grouping).
EXAMPLE
//
// moneypun.cpp
//
#include <string>
#include <iostream>
int main ()
{
using namespace std;
locale loc;
// Get a moneypunct facet
const moneypunct<char,false>& mp =
#ifndef _RWSTD_NO_TEMPLATE_ON_RETURN_TYPE
use_facet<moneypunct<char,false> >(loc);
#else
use_facet(loc,(moneypunct<char,false>*)0);
#endif
cout << "Decimal point = "
<< mp.decimal_point() << endl;
cout << "Thousands separator = "
<< mp.thousands_sep() << endl;
cout << "Currency symbol = "
<< mp.curr_symbol() << endl;
cout << "Negative Sign = "
<< mp.negative_sign() << endl;
cout << "Digits after decimal = "
<< mp.frac_digits() << endl;
return 0;
}
SEE ALSO
locale, facets, money_put, money_get