Re: [Boost-users] [Regex] Problem with optionality operator

./regex_test "Iphone" Output: No Match and Partial Match (Why is that? "Apple" is optional should only be "Partial Match")

No leading space in front of the "Iphone" compared to the regex which requires it as written.

./regex_test "Iphone 3g" Output: No Match and Partial Match (Why is that? "Apple" is optional should be "Full Match")

As above, your regex has a literal space in it which is not in the text. John.