Difference between range `save` and copy constructor

[uranuz]

In general for value-semantics and ref-semantics the different 
code is actually needed. But generic algorithm try to pretend 
that the logic is the same. But it's not true. But in wide subset 
of trivial algorithm it's true. So it's incorrectly interpolated 
that it's true for every case. The very bad thing if range is 
passed by value it still can have value or reference semantic. 
And algorithm cannot say which is it actually. There is not such 
problemme for classes. So as I already said when passing ranges 
by ref in algorithms they behave predictible. And if I want 
algrorithm to operate on copy of algorithm then I can just create 
this copy before passing it to this algorithm. And again 
intention is more clear. But Phobos algorithms don't work like 
that. It's why I can't use them in some cases, because they are 
looking unpredictable for me.