Fixed number input.

properInput.cpp

#include <iostream>
#include <string>
#include <sstream>

template <class T>
void readInto(T *var, const std::string &inputMessage, const std::string &errorMessage) {
  std::string input;

  while (true) {
    std::cout << inputMessage;
    getline(std::cin, input);

    std::stringstream s(input);
    if (s >> *var) return;
    std::cout << errorMessage << std::endl;
  }
}

int main(int argc, char const *argv[]) {
  std::string unos = "";
  int unos2 = 0;

  while (unos != "bye") {
    readInto(&unos2, "Unesite broj: ", "WUT?");
    std::cout << "Uneseno je '" << unos2 << "'." << std::endl;

    readInto(&unos, "Unesite tekst: ", "Smak svijeta!");
    std::cout << "Uneseno je '" << unos << "'." << std::endl;
  }

  return 0;
}