#include <iostream>
#include <string>

using namespace std;

template <typename Target, typename Source>
Target narrow_cast(Source src)
{
    Target tgt = src;

    if ((Source)tgt != src)
        throw string("Invalid narrowing conversion");

    return tgt;
}

int main() {
  try {
    int x=narrow_cast<int>(123456789.0);
    cout<<"narrow_cast 1 OK"<<endl;
    }
  catch (string e) {
    cout<<"narrow_cast 1 bonk "<<e<<endl;
    }

  try {
    int x=narrow_cast<int>(123456789.1);
    cout<<"narrow_cast 2 OK"<<endl;
    }
  catch (string e) {
    cout<<"narrow_cast 2 bonk "<<e<<endl;
    }

  try {
    char x=narrow_cast<char>(123);
    cout<<"narrow_cast 3 OK"<<endl;
    }
  catch (string e) {
    cout<<"narrow_cast 3 bonk "<<e<<endl;
    }

  try {
    char x=narrow_cast<char>(1234);
    cout<<"narrow_cast 4 OK"<<endl;
    }
  catch (string e) {
    cout<<"narrow_cast 4 bonk "<<e<<endl;
    }
  }