#include <iostream>
#include <limits>

using namespace std;

const char STOP_LETTER{'X'};

int main() {
   char letter;
   char upperLetter;

   cout << "Enter a character => ";
   cin.get(letter);
   cin.ignore(numeric_limits<std::streamsize>::max(),'\n');
   upperLetter = static_cast<char>(toupper(letter));

   while (cin and upperLetter != STOP_LETTER) {

       cout << "The character is '" <<  letter << '\'' << endl;
       cout << "The upper case version is '" << upperLetter << "'" << endl;
       cout << endl;

       if (isalpha(letter)) {
           cout << "It is a  letter" << endl;
           cout << endl;
       }

       if (isdigit(letter)) {
           cout << "It is a digit" << endl;
           cout << endl;
       } 

       if (isspace(letter)) {
           cout << "It is whitespace " << endl;
           cout << endl;
       }

       if (ispunct(letter)) {
           cout << "It is punctuation " << endl;
           cout << endl;
       }

       cout << endl << endl;
       cout << "Enter a character => ";
       cin.get(letter);
       cin.ignore(numeric_limits<std::streamsize>::max(),'\n');
       upperLetter = static_cast<char>(toupper(letter));
   }

   return 0;
}