I'd like to ask that a multibyte-safe version of trim() be added to PHP. If possible with this functionality:

String trim(string str, [string encoding], [string charlist])

1- automatically determine encoding of given string and remove that encoding's "whitespace". I.e if I pass an ASCII string it would act just as the current trim(), if I pass in an SJIS string it would remove whatever is considered "whitespace" for that character set (including full-width spaces).

Automatically determining the encoding of a string is not always possible, in that case the function promises only a "best guess" at the string's encoding.

2- Optional parameter that gives the string's encoding.

3- An optional list of characters to be considered "whitespace" instead of the function's built-in default list.