CPP/Strings/Case Conversion

1. include <string>
2. include <algorithm> // transform
3. include <functional> // ptr_fun
4. include <cctype> // toupper, tolower
5. include <iostream>

int main() {

   std::string clive = "Clive Cherishes Capitals",
               lewis = "Lewis LOVES Lowercase";

   // transform each character in 'clive' with 'toupper'
   std::transform(clive.begin(), clive.end(), clive.begin(),
                  std::ptr_fun<int,int>(std::toupper) );

   // transform each character in 'lewis' with 'tolower'
   std::transform(lewis.begin(), lewis.end(), lewis.begin(),
                  std::ptr_fun<int,int>(std::tolower) );

   std::cout << clive << std::endl;
   std::cout << lewis << std::endl;

}