Request for member X of Y which is of non-class type Z

When trying to compile the following snippet of C++ code (complete source below)

A::A(istream& i) {
    vector<string> words( istream_iterator<int>(i), istream_iterator<int> );
    words.begin();
 }

I'm getting the error

istream_it.cpp:12: error: request for member ‘begi开发者_高级运维n’ in ‘words’, which is of non-class type 
‘std::vector<int, std::allocator<int> >(
    std::istream_iterator<int, char, std::char_traits<char>, long int>,
    std::istream_iterator<int, char, std::char_traits<char>, long int>)’

I know this error is usually caused by accidentally declaring a function using the no-parameters operator, as in

string s(); s.size();

but in this case, I've already stripped all unnecessary code, and still cant see what exactly is going wrong, or what the correct syntax would be.

Full source:

#include <sstream>
#include <vector>
#include <iterator>
#include <string>

using namespace std;

class A {
public:
    A(istream& i) {
        vector<int> words(istream_iterator<int>(i), istream_iterator<int> );
        words.begin();
    }
};


int main(int argc, char** argv)
{
    istringstream iss("1 2 3");
    A a(iss);

    return 0;
}

Correct,

vector<int> words(istream_iterator<int>(i), istream_iterator<int> );

this is a function named words taking two istream_iterator<int> parameters, one of which named i and the other has no name, and returning vector. Change to this:

vector<int> words((istream_iterator<int>(i)), istream_iterator<int>() );

The first parentheses added (istream_iterator<int>(i)) make it an expression so there will be no ambiguity. The other parentheses istream_iterator<int>() are mandatory because you construct a temporary. A type by itself, like istream_iterator<int>, doesn't construct a temporary.