Standard C++ LibraryCopyright 1996, Rogue Wave Software, Inc.

NAME

  numpunct, numpunct_byname - Numeric punctuation facet.

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 delagated 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 seperator.  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 seperator = "
         << np.thousands_sep() << endl;
   cout << "True name           = "
         << np.truename() << endl;
   cout << "False name          = "
         << np.falsename() << endl;

   return 0;
  }

SEE ALSO

  locale, facets, num_put, num_get, ctype

STANDARDS CONFORMANCE

  ANSI X3J16/ISO WG21 Joint C++ Committee



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