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money_get Class

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The latest version of this topic can be found at money_get Class.

The template class describes an object that can serve as a locale facet to control conversions of sequences of type CharType to monetary values.

Syntax

template <class CharType, class InputIterator = istreambuf_iterator<CharType>>  
class money_get : public locale::facet;

Parameters

CharType
The type used within a program to encode characters in a locale.

InputIterator
The type of iterator from which the get functions read their input.

Remarks

As with any locale facet, the static object ID has an initial stored value of zero. The first attempt to access its stored value stores a unique positive value in id.

Constructors

money_get The constructor for objects of type money_get that are used to extract numerical values from sequences representing monetary values.

Typedefs

char_type A type that is used to describe a character used by a locale.
iter_type A type that describes an input iterator.
string_type A type that describes a string containing characters of type CharType.

Member Functions

do_get A virtual function called to extracts a numerical value from a character sequence that represents a monetary value.
get Extracts a numerical value from a character sequence that represents a monetary value.

Requirements

Header: <locale>

Namespace: std

money_get::char_type

A type that is used to describe a character used by a locale.

typedef CharType char_type;

Remarks

The type is a synonym for the template parameter CharType.

money_get::do_get

Virtual function called to extracts a numerical value from a character sequence that represents a monetary value.

virtual iter_type do_get(iter_type first,
    iter_type last,
    bool _Intl,
    ios_base& _Iosbase,
    ios_base::iostate& _State,
    long double& val) const virtual iter_type do_get(iter_type first,
    iter_type last,
    bool _Intl,
    ios_base& _Iosbase,
    ios_base::iostate& _State,
    string_type& val) const

Parameters

first
Input iterator addressing the beginning of the sequence to be converted.

last
Input iterator addressing the end of the sequence to be converted.

_Intl
A Boolean value indicating the type of currency symbol expected in the sequence: true if international, false if domestic.

_Iosbase
A format flag which when set indicates that the currency symbol is optional; otherwise, it is required.

_State
Sets the appropriate bitmask elements for the stream state according to whether the operations succeeded or not.

val
A string storing the converted sequence.

Return Value

An input iterator addressing the first element beyond the monetary input field.

Remarks

The first virtual protected member function tries to match sequential elements beginning at first in the sequence [ first, last) until it has recognized a complete, nonempty monetary input field. If successful, it converts this field to a sequence of one or more decimal digits, optionally preceded by a minus sign ( –), to represent the amount and stores the result in the string_type object val. It returns an iterator designating the first element beyond the monetary input field. Otherwise, the function stores an empty sequence in val and sets ios_base::failbit in _State. It returns an iterator designating the first element beyond any prefix of a valid monetary input field. In either case, if the return value equals last, the function sets ios_base::eofbit in _State.

The second virtual protected member function behaves the same as the first, except that if successful it converts the optionally signed digit sequence to a value of type long double and stores that value in val.

The format of a monetary input field is determined by the locale facetfac returned by the effective call use_facet < moneypunct< CharType, intl>>( iosbase. getloc).

Specifically:

  • fac. neg_format determines the order in which components of the field occur.

  • fac. curr_symbol determines the sequence of elements that constitutes a currency symbol.

  • fac. positive_sign determines the sequence of elements that constitutes a positive sign.

  • fac. negative_sign determines the sequence of elements that constitutes a negative sign.

  • fac. grouping determines how digits are grouped to the left of any decimal point.

  • fac. thousands_sep determines the element that separates groups of digits to the left of any decimal point.

  • fac. decimal_point determines the element that separates the integer digits from the fraction digits.

  • fac. frac_digits determines the number of significant fraction digits to the right of any decimal point. When parsing a monetary amount with more fraction digits than are called for by frac_digits, do_get stops parsing after consuming at most frac_digits characters.

If the sign string ( fac. negative_sign or fac. positive_sign) has more than one element, only the first element is matched where the element equal to money_base::sign appears in the format pattern ( fac. neg_format). Any remaining elements are matched at the end of the monetary input field. If neither string has a first element that matches the next element in the monetary input field, the sign string is taken as empty and the sign is positive.

If iosbase. flags & showbase is nonzero, the string fac. curr_symbol must match where the element equal to money_base::symbol appears in the format pattern. Otherwise, if money_base::symbol occurs at the end of the format pattern, and if no elements of the sign string remain to be matched, the currency symbol is not matched. Otherwise, the currency symbol is optionally matched.

If no instances of fac. thousands_sep occur in the value portion of the monetary input field (where the element equal to money_base::value appears in the format pattern), no grouping constraint is imposed. Otherwise, any grouping constraints imposed by fac. grouping is enforced. Note that the resulting digit sequence represents an integer whose low-order fac. frac_digits decimal digits are considered to the right of the decimal point.

Arbitrary white space is matched where the element equal to money_base::space appears in the format pattern, if it appears other than at the end of the format pattern. Otherwise, no internal white space is matched. An element ch is considered white space if use_facet < ctype< CharType> >( iosbase. getloc). is( ctype_base::space, ch) is true.

Example

See the example for get, which calls do_get.

money_get::get

Extracts a numerical value from a character sequence that represents a monetary value.

iter_type get(iter_type first,
    iter_type last,
    bool _Intl,
    ios_base& _Iosbase,
    ios_base::iostate& _State,
    long double& val) const;

iter_type get(iter_type first,
    iter_type last,
    bool _Intl,
    ios_base& _Iosbase,
    ios_base::iostate& _State,
    string_type& val) const;

Parameters

first
Input iterator addressing the beginning of the sequence to be converted.

last
Input iterator addressing the end of the sequence to be converted.

_Intl
A Boolean value indicating the type of currency symbol expected in the sequence: true if international, false if domestic.

_Iosbase
A format flag which when set indicates that the currency symbol is optional; otherwise, it is required

_State
Sets the appropriate bitmask elements for the stream state according to whether the operations succeeded.

val
A string storing the converted sequence.

Return Value

An input iterator addressing the first element beyond the monetary input field.

Remarks

Both member functions return do_get( first``, last``, _Intl, _Iosbase, _State, val).

Example

// money_get_get.cpp  
// compile with: /EHsc  
#include <locale>  
#include <iostream>  
#include <sstream>  
using namespace std;  
  
int main( )  
{  
   locale loc( "german_germany" );  
  
   basic_stringstream< char > psz;  
   psz << use_facet<moneypunct<char, 1> >(loc).curr_symbol() << "-1.000,56";  
   basic_stringstream< char > psz2;  
   psz2 << "-100056" << use_facet<moneypunct<char, 1> >(loc).curr_symbol();  
  
   ios_base::iostate st = 0;  
   long double fVal;  
  
   psz.flags( psz.flags( )|ios_base::showbase );   
   // Which forced the READING the currency symbol  
   psz.imbue(loc);  
   use_facet < money_get < char > >( loc ).  
      get( basic_istream<char>::_Iter( psz.rdbuf( ) ),     
           basic_istream<char>::_Iter( 0 ), true, psz, st, fVal );  
  
   if ( st & ios_base::failbit )  
      cout << "money_get(" << psz.str( ) << ", intl = 1) FAILED"  
           << endl;  
   else  
      cout << "money_get(" << psz.str( ) << ", intl = 1) = "   
           << fVal/100.0 << endl;  
  
   use_facet < money_get < char > >( loc ).  
      get(basic_istream<char>::_Iter(psz2.rdbuf( )),     
          basic_istream<char>::_Iter(0), false, psz2, st, fVal);  
  
   if ( st & ios_base::failbit )  
      cout << "money_get(" << psz2.str( ) << ", intl = 0) FAILED"   
           << endl;  
   else  
      cout << "money_get(" << psz2.str( ) << ", intl = 0) = "   
           << fVal/100.0 << endl;  
};

money_get::iter_type

A type that describes an input iterator.

typedef InputIterator iter_type;

Remarks

The type is a synonym for the template parameter InputIterator.

money_get::money_get

The constructor for objects of type money_get that are used to extract numerical values from sequences representing monetary values.

explicit money_get(size_t _Refs = 0);

Parameters

_Refs
Integer value used to specify the type of memory management for the object.

Remarks

The possible values for the _Refs parameter and their significance are:

  • 0: The lifetime of the object is managed by the locales that contain it.

  • 1: The lifetime of the object must be manually managed.

  • > 0: These values are not defined.

No direct examples are possible, because the destructor is protected.

The constructor initializes its base object with locale::facet( **_**Refs).

money_get::string_type

A type that describes a string containing characters of type CharType.

typedef basic_string<CharType, Traits, Allocator> string_type;

Remarks

The type describes a specialization of template class basic_string.

See Also

<locale>
facet Class
Thread Safety in the C++ Standard Library