istream_iterator::istream_iterator
Constructs either an end-of-stream iterator as the default istream_iterator or a istream_iterator initialized to the iterator's stream type from which it reads.
istream_iterator( );
istream_iterator(
istream_type& _Istr
);
Parameters
- _Istr
The input stream to be read use to initialize the istream_iterator.
Remarks
The First constructor initializes the input stream pointer with a null pointer and creates an end-of-stream iterator. The second constructor initializes the input stream pointer with &_Istr, then attempts to extract and store an object of type Type.
The end-of-stream iterator can be use to test whether an istream_iterator has reached the end of a stream.
Example
// istream_iterator_istream_iterator.cpp
// compile with: /EHsc
#include <iterator>
#include <vector>
#include <algorithm>
#include <iostream>
int main( )
{
using namespace std;
// Used in conjunction with copy algorithm
// to put elements into a vector read from cin
vector<int> vec ( 4 );
vector <int>::iterator Iter;
cout << "Enter 4 integers separated by spaces & then\n"
<< " a character ( try example: '2 4 6 8 a' ): ";
istream_iterator<int> intvecRead ( cin );
// Default constructor will test equal to end of stream
// for delimiting source range of vecor
copy ( intvecRead , istream_iterator<int>( ) , vec.begin ( ) );
cin.clear ( );
cout << "vec = ";
for ( Iter = vec.begin( ) ; Iter != vec.end( ) ; Iter++ )
cout << *Iter << " "; cout << endl;
}
2 4 6 8 a
Enter 4 integers separated by spaces & then
a character ( try example: '2 4 6 8 a' ): 2 4 6 8 a
vec = 2 4 6 8
Requirements
Header: <iterator>
Namespace: std