[Boost-users] [GIL] gil_function_requires( view that contains alpha )

Hi everybody, I would like to know if there is an easy way to check if a view type contains an alpha channel. I would do something like that (not tested): BOOST_STATIC_ASSERT(mpl::contains<typename color_space_type<Pixel>::type, alpha_t>::value); But I don't know if it is a good idea. Is there a way to do that with gil_function_requires ? Thanks & respect ! Eloi.