depends boost && depends -sub CXX gcc && depends pkgconfig && depends zlib '--with-z=yes' && optional_depends JPEG \ '--with-jpeg=yes' \ '--with-jpeg=no' \ 'for JPEG image support' && optional_depends libpng \ '--with-png=yes' \ '--with-png=no' \ 'for PNG image support' && optional_depends tiff \ '--with-tiff=yes' \ '--with-tiff=no' \ 'for TIFF image support'