Is string::compare reliable to determine alphabetical order?

Question

Simply put, if the input is always in the same case (here, lower case), and if the characters are always ASCII, can one use string::compare to determine reliably the alphabetica

Answer 1

yes,

The member function returns 0 if all the characters in the compared contents compare equal, a negative value if the first character that does not match compares to less in the object than in the comparing string, and a positive value in the opposite case.

For string objects, the result of a character comparison depends only on its character code (i.e., its ASCII code), so the result has some limited alphabetical or numerical ordering meaning.