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

In C++, string is the instantiation of the template class basic_string with the default parameters: basic_string, allocator >. The compare function in the basic_string template will use the char_traits::compare function to determine the result value.

For std::string the ordering will be that of the default character code for the implementation (compiler) and that is usually ASCII order. If you require a different ordering (say you want to consider { a, á, à, â } as equivalent), you can instantiate a basic_string with your own char_traits<> implementation. providing a different compare function pointer.