const-correctness in std.range

[Vlad Levenfeld via Digitalmars-d-learn]

Thanks for the reply.

And indeed, I recently found that ByLine.empty can't be const 
because it writes and removes a character from the stream or 
something... and when I compile with optimizations, const empty 
gets totally wrecked.

I suppose that making empty const doesn't really gain me 
anything, as its generally used in conjunction with popFront 
which is obviously non-const.