Transforms a string as a list of strings separated by `|`` where all combinations of character cases are generated. By construction first one is fully uppercase, second one is fully lowercase.
The following call:
match value.as_ref() {
choice_nocase!("hi") => println!("good"),
_ => println!("bad")
};
corresponds to a similar macro expansion:
match value.as_ref() {
"HI" | "hi" | "Hi" | "hI" => println!("good"),
_ => println!("bad")
};