Remove single trailing newline from String without cloning

Question

I have written a function to prompt for input and return the result. In this version the returned string includes a trailing newline from the user. I would like to return th

Answer 1

A cross-platform way of stripping a single trailing newline without reallocating the string is this:

fn trim_newline(s: &mut String) {
    if s.ends_with('\n') {
        s.pop();
        if s.ends_with('\r') {
            s.pop();
        }
    }
}

This will strip either "\n" or "\r\n" from the end of the string, but no additional whitespace.