Description:
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Hello!

As mentioned in the documentation[1]: "PHP will fall back to global functions or constants if a namespaced function or constant does not exist". A "fall back" implies (?) more computation (in this case going through the priority list) which further implies a loss of speed/performance.

It should be mentioned in the doc - if my assumption is true (based on a excerp of the internals-mailinglist[2]), that calling a built in function fully qualified (\built_in_function()) should be prefered over unqualified (built_in_function()).

I know, this is just a small note to the doc, but built-in functions are used very often, so this could bring a lot of speed on medium to large projects.

May add this to the doc when 5.3 is out and/or when it's clear how, what and when a fallback will be used (see discussion[3]).

Regards
David

[1] http://www.php.net/namespaces.fallback
[2] http://news.php.net/php.internals/41696
[3] http://wiki.php.net/rfc/namespaceresolution