http://www.boost.org/doc/libs/1_43_0/libs/preprocessor/doc/ref/tuple_rem.html

or

http://www.boost.org/doc/libs/1_43_0/libs/preprocessor/doc/ref/tuple_rem_ctor.html

Could help you.

> To: boost-users@lists.boost.org
> From: eldiener@tropicsoft.com
> Date: Wed, 4 Aug 2010 16:05:57 -0400
> Subject: [Boost-users] [preprocessor] removing parentheses
>
> I have a single macro parameter which allows its passed value to contain
> commas. Therefore the user of the macro needs parentheses around the
> parameter if it contains one or more commas ( to does not have to ).
> When processing this parameter in a macro I would like to remove the
> outer parentheses if they are there before passing the value on for
> further processing. Is there a way to do this using some preprocessor
> library macro ?
>
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