Поиск в строке гласных и согласных - C++

#include <algorithm>
#include <iostream>
#include <string>
#include <cctype>
 
bool IsVowel(char ch) {
  const std::string vowels = "AEIOUY";
  return vowels.find_first_of(std::toupper(ch)) != std::string::npos;
}
 
bool IsConsonant(char ch) {
  const std::string consonants = "BCDFGHJKLMNPQRSTVWXZ";
  return consonants.find_first_of(std::toupper(ch)) != std::string::npos;
}
 
int main() {
  const std::string str = "This is the test string";
  
  std::cout << "Vowel count: "      <<
               std::count_if(str.begin(), str.end(), IsVowel)     << std::endl;
  std::cout << "Consonants count: " <<
               std::count_if(str.begin(), str.end(), IsConsonant) << std::endl;
               
  return 0;
}