This way you either have to declare every type you want to use this with at file scope (which is fine and some people do this, but it's a little irksome), or no

This way you either have to declare every type you want to use this with at file scope (which is fine and some people do this, but it's a little irksome), or not be able to pass them as parameters to functions. Also it doesn't solve the problem of function genericity.