moneypunct(3C++)

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 enumeration 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 FLAGMEANING

noneNo grouping separator

spaceUse space for grouping separator

symbolCurrency symbol

signSign of monetary value

valueThe 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

};

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 public 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 particular 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 unlimited. 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 characters, 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 restrictions, 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 characters, 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;

}

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