ostream_iterator(3C++) - ostream_iterator(3C++)
Standard C++ Library Copyright 1998, Rogue Wave Software, Inc.
NAMEostream_iterator
- Stream iterators allow for use of iterators with ostreams and
istreams. They allow generic algorithms to be used directly on streams.
SYNOPSIS
#include <ostream>
template <class T, class charT,
class traits = char_traits<charT> >
class ostream_iterator
: public iterator<output_iterator_tag,void,void>;
DESCRIPTION
Stream iterators use the standard iterator interface for input and out‐
put streams.
The class ostream_iterator writes elements to an output stream. If you
use the constructor that has a second char * argument, then that string
is written after every element (the string must be null-terminated).
Since an ostream iterator is an output iterator, it is not possible to
get an element out of the iterator. You can only assign to it.
INTERFACEtemplate <;class T, class charT,
class traits = char_traits<charT> >
class ostream_iterator
: public iterator<output_iterator_tag,void,void>
{
public:
typedef T value_type;
typedef charT char_type;
typedef traits traits_type;
typedef basic_ostream<charT,traits> ostream_type;
ostream_iterator(ostream&);
ostream_iterator (ostream&, const char*);
ostream_iterator (const
ostream_iterator<T,charT,char_traits<charT> >&);
~ostream_itertor ();
ostream_iterator<T,charT,char_traits<charT> >&
operator=(const T&);
ostream_iterator<T,charT,char_traits<charT> >&
operator* () const;
ostream_iterator<T,charT,char_traits<charT> >&
operator++ ();
ostream_iterator<T,charT,char_traits<charT> >
operator++ (int);
};
TYPESvalue_type;
Type of value to stream in.
char_type;
Type of character the stream is built on.
traits_type;
Traits used to build the stream.
ostream_type;
Type of stream this iterator is constructed on.
CONSTRUCTORSostream_iterator (ostream& s);
Constructs an_ostream_iterator on the given stream.
ostream_iterator (ostream& s, const char* delimiter);
Constructs an_ostream_iterator on the given stream. The null terminated
string delimiter is written to the stream after every element.
ostream_iterator (const ostream_iterator<;T>& x);
Copy constructor.
DESTRUCTORS
~ostream_iterator ();
Destroys an object of class ostream_iterator.
OPERATORS
const T& <br>operator= (const T& value);
Shift the value T onto the output stream.
const T& ostream_iterator<;T>&
operator* ();
ostream_iterator<;T>&
operator++();
ostream_iterator<;T>
operator++ (int);
These operators do nothing. They simply allow the iterator to be used in
common constructs.
EXAMPLE
#include <iterator>
#include <numeric>
#include <deque>
#include <iostream>
using namespace std;
int main ()
{
//
// Initialize a vector using an array.
//
int arr[4] = { 3,4,7,8 };
int total=0;
deque<int> d(arr+0, arr+4);
//
// stream the whole vector and a sum to cout
//
copy(d.begin(),d.end()-1,
ostream_iterator<int,char>(cout," + "));
cout << *(d.end()-1) << " = " <<
accumulate(d.begin(),d.end(),total) << endl;
return 0;
}
WARNINGS
If your compiler does not support default template parameters, then you
always need to supply the Allocator template argument. For instance,
you need to write:
deque<int, allocator<int> >
instead of:
deque<int>
If your compiler does not support namespaces, then you do not need the
using declaration for std.
SEE ALSO
istream_iterator, Iterators
Rogue Wave Software 02 Apr 1998 ostream_iterator(3C++)
