Hi,

In message "Re: String#insert method is destructive...  inconsistent?"
    on Fri, 15 Dec 2006 07:48:25 +0900, Joe Peterson <joe / lavajoe.com> writes:

|Almost all others (and all that might be ambiguous), like "delete",
|"sub", etc., have both the non-destructive and destructive versions
|("delete", "delete!", etc.).

concat is destructive as well.

							matz.