#include <iostream>
using std::cout;
using std::endl;
#include <string>
using std::string;
int main()
{
string string1( "This is a test string!");
int location;
location = string1.find_first_of( "is" );
cout << "\n\n(find_first_of) found '" << string1[ location ]
<< "at: " << location;
return 0;
}