Pangram checker

You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.

For example:   The quick brown fox jumps over the lazy dog.



Task

Write a function or method to check a sentence to see if it is a   pangram   (or not)   and show its use.



Related tasks

   determine if a string has all the same characters
   determine if a string has all unique characters


#include <algorithm>
#include <cctype>
#include <string>
#include <iostream>
 
const std::string alphabet("abcdefghijklmnopqrstuvwxyz");
 
bool is_pangram(std::string s)
{
    std::transform(s.begin(), s.end(), s.begin(), ::tolower);
    std::sort(s.begin(), s.end());
    return std::includes(s.begin(), s.end(), alphabet.begin(), alphabet.end());
}
 
int main()
{
    const auto examples = {"The quick brown fox jumps over the lazy dog",
                           "The quick white cat jumps over the lazy dog"};
 
    std::cout.setf(std::ios::boolalpha);
    for (auto& text : examples) {
        std::cout << "Is \"" << text << "\" a pangram? - " << is_pangram(text) << std::endl;
    }
}
 