Transience of .front in input vs. forward ranges

[Tommi]

On Tuesday, 6 November 2012 at 04:31:56 UTC, H. S. Teoh wrote:
> The problem is that you can't do this in generic code, because 
> generic code by definition doesn't know how to copy an
> arbitrary type.

I'm not familiar with that definition of generic code. But I do 
feel that there's a pretty big problem with a language design if 
the language doesn't provide a generic way to make a copy of a 
variable. To be fair, e.g. C++ doesn't provide that either.