numpunct, numpunct

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numpunct, numpunct_byname


 numpunctlocale::facet

Summary

Data Type and Member Function Indexes

Constructors and Destructors

Facet ID

Public Member Functions

Protected Member Functions

Example

Summary

Numeric punctuation facet.

Data Type and Member Function Indexes
(exclusive of constructors and destructors)

Data Types

char_type

Member Functions

decimal_point()
do_decimal_point()
do_falsename()
do_grouping()
do_thousands_sep()
do_truename()
falsename()
grouping()
thousands_sep()
truename()

Synopsis

#include <locale>
template <class charT>  class numpunct;
template <class charT>  class numpunct_byname;

Description

The numpunct<charT> facet specifies numeric punctuation. This template provides punctuation based on the "C" locale, while the numpunct_byname facet provides the same facilities for named locales.

Both num_put and num_get make use of this facet.

Interface

template <class charT>
class numpunct : public locale::facet {
public:
  typedef charT               char_type;
  typedef basic_string<charT> string_type;
  explicit numpunct(size_t refs = 0);
  char_type    decimal_point()   const;
  char_type    thousands_sep()   const;
  string       grouping()        const;
  string_type  truename()        const;
  string_type  falsename()       const;
  static locale::id id;
protected:
  ~numpunct();  // virtual
  virtual char_type    do_decimal_point() const;
  virtual char_type    do_thousands_sep() const;
  virtual string       do_grouping()      const;
  virtual string_type  do_truename()      const;  // for bool
  virtual string_type  do_falsename()     const;  // for bool
};

template <class charT>
class numpunct_byname : public numpunct<charT> {
public:
  explicit numpunct_byname(const char*, size_t refs = 0);
protected:
  ~numpunct_byname();  // virtual
  virtual char_type    do_decimal_point() const;
  virtual char_type    do_thousands_sep() const;
  virtual string       do_grouping()      const;
  virtual string_type  do_truename()      const;  // for bool
  virtual string_type  do_falsename()     const;  // for bool
};

Types

char_type

Type of character upon which the facet is instantiated.

string_type

Type of character string returned by member functions.

Constructors and Destructors

explicit numpunct(size_t refs = 0)

Construct a numpunct 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 had, if refs is 1 then the object must be explicitly deleted; the locale will not do so. In this case, the object can be maintained across the lifetime of multiple locales.

explicit numpunct_byname(const char* name, size_t refs = 0);

Construct a numpunct_byname facet. Use the named locale specified by the name argument. The refs argument serves the same purpose as it does for the numpunct constructor.

~numpunct();  // virtual and protected
~numpunct_byname();  // virtual and protected

Destroy the facet

Facet ID

static locale::id id;

Unique identifier for this type of facet.

Public Member Functions

The public members of the numpunct facet provide 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 grouping function simply calls its protected cousin do_grouping.

char_type    decimal_point()   const;
string_type  falsename()       const;
string       grouping()        const;
char_type    thousands_sep()   const;
string_type  truename()        const;

Each of these public member functions xxx simply call the corresponding protected do_xxx function.

Protected Member Functions

virtual char_type    
do_decimal_point() const;

Returns the decimal radix separator . numpunct returns '.'.

virtual string_type  
do_falsename()     const;  // for bool
virtual string_type  
do_truename()      const;  // for bool

Returns a string representing the name of the boolean values true and false respectively . numpunct returns "true" and "false".

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. numpunct returns an empty string, indicating no grouping.

virtual char_type    
do_thousands_sep() const;

Returns the decimal digit group separator. numpunct returns ','.

Example

//
// numpunct.cpp
//

#include <iostream>

int main ()
{
  using namespace std;
  locale loc;

  // Get a numpunct facet
  const numpunct<char>& np = 
#ifndef _RWSTD_NO_TEMPLATE_ON_RETURN_TYPE
  use_facet<numpunct<char> >(loc);
#else
  use_facet(loc,(numpunct<char>*)0);
#endif

  cout << "Decimal point       = " 
       << np.decimal_point() << endl; 
  cout << "Thousands separator = " 
       << np.thousands_sep() << endl; 
  cout << "True name           = " 
       << np.truename() << endl; 
  cout << "False name          = " 
       << np.falsename() << endl; 

  return 0;
}