num_put

 num_putlocale::facet

• Summary
• Data Type and Member Function Indexes
• Synopsis
• Description
• Interface
• Types
• Constructors and Destructors
• Facet ID
• Public Member Functions
• Protected Member Functions
• Example
• See Also

Numeric formatting facet for output.

Data Types

char_type id iter_type

Member Functions

do_put() put()

#include <locale>
template <class charT, class OutputIterator> class num_put;

The num_put<charT,OutputIterator> template provides facilities for formatted output of numbers. basic_ostream and all other input oriented streams use this facet to implement formatted numeric output.

template <class charT, class OutputIterator = ostreambuf_iterator<charT> >
class num_put : public locale::facet {
public:
  typedef charT            char_type;
  typedef OutputIterator   iter_type;
  explicit num_put(size_t = 0);

  iter_type put(iter_type, ios_base&, char_type, bool) const;
  iter_type put(iter_type, ios_base&, char_type, long) const;
  iter_type put(iter_type, ios_base&, char_type,
                unsigned long) const;
  iter_type put(iter_type, ios_base&, char_type,
                double) const;
  iter_type put(iter_type, ios_base&, char_type,
                long double) const;
  static locale::id id;

protected:
  ~num_put();  // virtual
  virtual iter_type do_put(iter_type, ios_base&, char_type,
                           bool) const;
  virtual iter_type do_put(iter_type, ios_base&, char_type,
                           long) const;
  virtual iter_type do_put(iter_type, ios_base&, char_type,
                           unsigned long) const;
  virtual iter_type do_put(iter_type, ios_base&, char_type,
                           double) const;
  virtual iter_type do_put(iter_type, ios_base&, char_type,
                           long double) const;
};

char_type

Type of character upon which the facet is instantiated.

iter_type

Type of iterator used to scan the character buffer.

explicit num_put(size_t refs = 0)

Construct a num_put 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.

~num_put();  // virtual and protected

Destroy the facet

static locale::id id;

Unique identifier for this type of facet.

The public members of the num_put 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 put function simply calls its protected cousin do_put.

iter_type 
put(iter_type s, ios_base& io, char_type fill, bool v) const;
iter_type 
put(iter_type s, ios_base& io, char_type fill, long v) const;
iter_type 
put(iter_type s, ios_base& io, char_type fill,
    unsigned long v) const;
iter_type 
put(iter_type s, ios_base& io, char_type fill, double v) const;
iter_type
put(iter_type s, ios_base& io, char_type fill, long double v) const;

virtual iter_type 
do_put(iter_type s, ios_base& io, 
       char_type fill, bool v) const;
virtual iter_type 
do_put(iter_type s, ios_base& io, 
       char_type fill, long v) const;
virtual iter_type 
do_put(iter_type s, ios_base& io, 
       char_type fill,unsigned long) const;
virtual iter_type 
do_put(iter_type s, ios_base& io, 
       char_type fill, double v) const;
virtual iter_type 
do_put(iter_type s, ios_base& io, 
       char_type fill,long double v) const;

//
// numput.cpp
//

#include <iostream>

int main ()
{
  using namespace std;

  typedef ostreambuf_iterator<char,char_traits<char> > iter_type;
  
  locale loc;
  bool bval = true;
  long lval = 422432L;
  unsigned long ulval = 12328889UL;
  double dval = 10933.8934; 
  long double ldval = 100028933.8934; 

  // Construct a ostreambuf_iterator on cout
  iter_type begin(cout);

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

  // Put out a bool
  cout << bval << " --> ";
  np.put(begin,cout,' ',bval);

  // Put out a long
  cout << endl << lval << " --> ";
  np.put(begin,cout,' ',lval);

  // Put out an unsigned long
  cout << endl << ulval << " --> ";
  np.put(begin,cout,' ',ulval);

  // Put out a double
  cout << endl << dval << " --> ";
  np.put(begin,cout,' ',dval);

  // Put out a long double
  cout << endl << ldval << " --> ";
  np.put(begin,cout,' ',ldval);

  cout <<  endl;

  return 0;
}

locale, facets, numget, numpunct, ctype

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