how to test if a character is a vowel in cpp code example

Example: is vowel c++

// c is a char
auto isLowercaseVowel = (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u');
auto isUppercaseVowel = (c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U');