"BCS" <ao at pathlink.com> wrote in message news:ce0a3343c58c8c9a19db144d622 at news.digitalmars.com... > might this work? (I haven't tried it yet) > > template T(F) > { > staic if(is(F R == function)) > else > static assert(false); > } shorter: template T(F) { static assert(is(F == function)); }