Regular expression - PCRE (PHP) - word boundary (\b) and accent characters

Question

Why does the letter é count as a word boundary matching \b in the following example?

Pattern: /\b(cum)\b/i

Text: écumé

Matches 'cum' which is not desired.

Is it possible to overcome this?

Answer 1

It will work, when you add the u modifier to your regex

/\b(cum)\b/iu

Answer 2

To deal with unicode, replace \b with

/(?<=^|\PL)(cum)(?=\PL|$)/i