error in reading input stream read in c++ with visual studio code

Question

#include<iostream>
#include<string>
#include<cstdlib>
#include<sstream>
#include<vector>
#include <iterator>
using namespace std;

int main()
{
    string str;
    unsigned int i;
    vector<string> arr;
    getline(cin,str);

    istringstream it(str);
    vector<string> arr(istream_iterator<string>(),istream_iterator<string>(it));
    arr.push_back('\0');

    //boost::split(arr, str, [](char c){return c == ' ';});
    //auto splitText = str | view::split(' ');
    for(i=0; i<arr.size(); i++){
        cout<<arr[i]<<endl;
    }

    return 0;
}

The above code shows an error as follows: error: 'std::vector > arr(std::istream_iterator > (*)(), std::istream_iterator >)' redeclared as different kind of symbol

when building with g++. Any help or hint would be highly appreciated.

Answer 1

When running g++, it also hints at where the problem lies:

a.cpp:13:20: note: previous declaration 'std::vector<std::__cxx11::basic_string<char> > arr' 
     vector<string> arr; 
                    ^~~

This means, you declared arr twice. First at line 13 and a second time at 17. This is what

redeclared as different kind of symbol

means.

---

Removing the first declaration at line 13, fixes this error message, but reveals the next problem

a.cpp:18:9: error: request for member 'push_back' in 'arr', which is of non-class type 'std::vector<std::__cxx11::basic_string<char> >(std::istream_iterator<std::__cxx11::basic_string<char> > (*)(), std::istream_iterator<std::__cxx11::basic_string<char> >)'
 arr.push_back('\0');
     ^~~~~~~~~

This is more complicated, and is why @DietmarKühl closed the question as a duplicate to question Most vexing parse: why doesn't A a(()); work?. The second answer is the most useful in this case and solves it by using curly braces around the parameters

vector<string> arr{istream_iterator<string>(),istream_iterator<string>(it)};