finishing cin stream after getting values by istream_iterator

Question

I have a simple question concerning iterator , in the following code I used three ways to get values from the pointer of iterator and put them into standard output or into vector , but the cin stream is continuous even after pressing enter key. what should be the bug in this code.... Thanks in advance

#include <iostream>
#include <iterator>
#include <vector>

using namespace std;

int main()
{

    vector<double> My_container ;

    cout << "Enter values separated by spaces : " ;


#define code1

#ifdef code1

    copy (istream_iterator<double>(cin),
          istream_iterator<double>(),
          ostream_iterator<double>(cout)) ;    

#endif // code


/////////////////////////////////////////////////////
#ifdef code2

    istream_iterator<double> eos ;
    istream_iterator<double> basic_input (cin);    

    while (basic_input != eos)
    {
        My_container.push_back(*basic_input) ;
        ++basic_input ;    
    }

    for (int i = 0 ; i < My_container.size() ; i++)
    {
        cout << i << " :" << My_container.at(i) << endl ;
    }

#endif //code2


//////////////////////////////////////////////
#ifdef code3

    istream_iterator<double> stream_end ;
    istream_iterator<double> basic_input (cin);    

    for ( ; basic_input != stream_end; ++basic_input )
    {
        My_container.push_back(*basic_input) ;
    }

    for (int i = 0 ; i < My_container.size() ; i++)
    {
        cout << i << " :" << My_container.at(i) << endl ;
    }

#endif //code3

}

Answer 1

You are waiting for eof in order to close the stream. Pressing enter won't do, it simply puts a newline character in the stream.

You will either have to check for a newline, or signal eof yourself.