money_get(3C++)

Standard C++ Library
Copyright 1998, Rogue Wave Software, Inc.

NAME

money_get

- Monetary formatting facet for input.

SYNOPSIS

#include <locale>
template <class charT,

class InputIterator = istreambuf_iterator<charT> >

class money_get;

DESCRIPTION

The money_get_facet interprets formatted monetary string values.

INTERFACE

template <class charT,

class InputIterator = istreambuf_iterator<charT> >

class money_get : public locale::facet {
public:

typedef charT char_type;
typedef InputIterator iter_type;
typedef basic_string<charT> string_type;
explicit money_get(size_t = 0);
iter_type get(iter_type, iter_type, bool, ios_base&,

ios_base::iostate&, long double&) const;

iter_type get(iter_type, iter_type, bool, ios_base&,

ios_base::iostate&, string_type&) const;

static locale::id id;

protected:

~money_get(); // virtual

virtual iter_type do_get(iter_type, iter_type,

bool, ios_base&,
ios_base::iostate&,
long double&) const;

virtual iter_type do_get(iter_type, iter_type,

bool, ios_base&,
ios_base::iostate&,
string_type&) const;

};

TYPES

char_type

Type of character upon which the facet is instantiated.

iter_type

Type of iterator used to scan the character buffer.

string_type

Type of character string passed to member functions.

CONSTRUCTORS

explicit money_get(size_t refs = 0)

Construct a money_get 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.

DESTRUCTORS

~money_get(); // virtual and protected

Destroys the facet.

STATIC MEMBERS

static locale::id id;

Unique identifier for this type of facet.

PUBLIC MEMBER FUNCTIONS

The public members of the money_get facet include an interface to protected members. Each public member get has a corresponding virtual protected member do_get.

iter_type
get(iter_type s, iter_type end, bool intl, ios_base& f,

ios_base::iostate& err, long double& units) const;

iter_type
get(iter_type s, iter_type end, bool intl, ios_base& f,

ios_base::iostate& err, string_type& digits) const;

Each of these two overloads of the public member function get calls the corresponding protected do_get function.

PROTECTED MEMBER FUNCTIONS

virtual iter_type
do_get(iter_type s, iter_type end,

bool intl, ios_base& f,
ios_base::iostate& err,
long double& units) const;

virtual iter_type
do_get(iter_type s, iter_type end,

bool intl, ios_base& f,
ios_base::iostate& err,
string_type& digits) const;

Reads in a localized character representation of a monetary value and generates a generic representation, either as a sequence of digits or as a long double value. In either case do_get uses the smallest possible unit of currency.

Both overloads of do_get read characters from the range [s,end) until one of three things occurs:

-A monetary value is assembled

-An error occurs

-No more characters are available.

The functions use f.flags() and the moneypunct<charT, true> or moneypunct<charT, false> facet (depending on the intl argument) from f.getloc() for formatting information to use in interpreting the sequence of characters. do_get, then places a pure sequence of digits representing the monetary value in the smallest possible unit of currency into the string argument digits, or it calculates a long double value based on those digits and returns that value in units.

The following specifics apply to formatting:

-Digit group separators are optional. If no grouping is specified, then any thousands separator characters are treated as delimiters.

-If space or none are part of the format pattern in moneypunct, then optional whitespace is consumed, except at the end. See the moneypunct reference section for a description of money-specific formatting flags.

-If iosbase::showbase is set in f.flags(), then the currency symbol is optional, and if it appears after all other elements, then it is not consumed. Otherwise the currency symbol is required, and is consumed wherever it occurs.

-digits are preceded by a ‘-’ or units are negated, if the monetary value is negative.

-See the moneypunct reference section for a description of money specific formatting flags.

The err argument is set to iosbase::failbit if an error occurs during parsing.

Returns an iterator pointing one past the last character that is part of a valid monetary sequence.

EXAMPLE

//
// moneyget.cpp
//

#include <string>
#include <sstream>
using namespace std;

int main ()
{

using namespace std;
typedef istreambuf_iterator<char,char_traits<char> >

iter_type;

locale loc;
string buffer("$100.02");
string dest;
long double ldest;
ios_base::iostate state;
iter_type end;

// Get a money_get facet

const money_get<char,iter_type>& mgf =

#ifndef _RWSTD_NO_TEMPLATE_ON_RETURN_TYPE

use_facet<money_get<char,iter_type> >(loc);

#else

use_facet(loc,(money_get<char,iter_type>∗)0);

#endif

{

// Build an istringstream from the buffer and construct
// a beginning iterator on it.

istringstream ins(buffer);
iter_type begin(ins);

// Get a string representation of the monetary value

mgf.get(begin,end,false,ins,state,dest);

}
{

// Build another istringstream from the buffer, etc.
// so we have an iterator pointing to the beginning

istringstream ins(buffer);
iter_type begin(ins);

// Get a long double representation
// of the monetary value

mgf.get(begin,end,false,ins,state,ldest);

}

cout << buffer << " --> " << dest

<< " --> " << ldest << endl;

return 0;

}

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