Enabling C++11 in Eclipse Mars permanently

I am using Eclipse for c++ and trying to use c++ 11 and getting error.How can i convert c++ 98 to c++11 permanently not only just for a package. I found this answer Enabling C++11 in Eclipse Juno/Kepler/Luna CDT but here was discused for only a package.But i want to set it permanently.ie

#include <vector>
#include <iostream>

int main()
{
   std::vector<int> fibonacci = { 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89 }; 
    for (const auto &number : fibonacci)
    std::cout << number << ' ';

  return 0;
}

This code isn't working in Eclipse for the reason of c++ 98.