improvement request - enabling by-value-containers

[Jonathan Schmidt-Dominé]

> A partial (but maybe better) solution to this problem is to introduce
> "linear types" in D, ad then let the compiler allocate a container on the
> stack as an automatic optimization where possible:
> http://en.wikipedia.org/wiki/Linear_types

Well, then you would have a lot of null-ptrs when using the by-reference-
containers, not very intuitive. What should it be good for?