On Tue, Dec 1, 2020 at 10:25 AM Marco Sulla
<marco.sulla.pyt...@gmail.com> wrote:
>
> On Mon, 30 Nov 2020 at 23:26, David Mertz <me...@gnosis.cx> wrote:
> > Somehow "dire" doesn't strike me as the right word.... Maybe you were 
> > looking for "conceivably useful in niche cases."?
>
> Well, I think const can be useful for:
> * multiprocessing. Now, for example, dict is passed between processes
> using MappingProxyType, which is slow.
> * avoid side effects. I expect that my object will not change and I
> want to be sure I'll not change it by mistake. Mistake that I made a
> lot of times.
> * contract. A function marks a parameter as const will guarantee that
> the object will not be changed. It's something complementar to
> annotations.
> * possible future speed improvements. For example, if an iterable is
> const, you can skip a lot of checks about mutability on iteration and
> make it more fast.

Are you assuming that "const" means "will not be rebound" or "is
immutable"? Or both?

ChrisA
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