#include <cctype>
    int toupper( int char );

  Returns upper case type of the character

#include <iostream> /* including standard library */
#include <cctype>
 
using namespace std;
int main ( void )
{
  /* convert the Chars "i" and "t" uppercase  */
  cout << static_cast<char>(toupper('i')) << " whant " << static_cast<char>(toupper('t')) << "his in uppercase" << endl;
 
return 0;
}

  output:
  I whant This in uppercase