Michel Fortin wrote:
On 2010-01-01 15:53:42 -0500, Andrei Alexandrescu
<[email protected]> said:
save() is not only for classes. It also distinguishes input ranges
from forward ranges. It's the primitive that STL didn't define but
should have.
Right. I still maintain that it's a bad approach. I've written a lot of
algorithms in C++ that worked with iterators, always assuming assignment
would copy the state. Fortunately I didn't had to use input iterators
with them, most of the time. But I did once or twice, and the thing was
working slightly off.
What I'd do instead is somehow make input ranges non-copyable. They
could be either passed by ref or moved, never copied. This way they
would still behave exactly like array slices, only not copyable, and you
get a compile-time error if you try to copy them which is infinitely
better than a subtle change in behavior.
I tried that, it makes input ranges next to unusable. save() is an
imperfect but workable solution.
Andrei
