+m4_copy([AC_ARG_WITH], [save_AC_ARG_WITH])
+m4_pushdef([AC_ARG_WITH], [m4_case([$1], [x],
+ [m4_popdef([$0])$0([x], AS_HELP_STRING([--with-x],
+ [build UI for the X Window System (default: auto)]), m4_shift2($@))],
+ [m4_pushdef([$0], m4_defn([save_$0]))$0($@)m4_popdef([$0])])])