Idiomatic string parmeter types: &str vs AsRef<str> vs Into<String>

[kamalmarhubi]

@BurntSushi

The regex crate, for example, is not allocation free and the computation and memory required for compiling a regex dwarfs the overhead of creating a copy of the pattern string itself.

This is a good point. Perhaps Into<String> is enough for this use case, as it's more or less a construct-time-only of long-lived, rarely constructed beyond startup structs.