On Friday, 15 July 2016 at 15:35:37 UTC, Dicebot wrote:
One example is if you make a class that has an internal cache
of something. Updating or invalidating that cache has no
logical effect on the externally-observable state of the
class. So you should be able to modify the cache even on a
'const' object. This is not a bug and I've seen it have a huge
effect on performance - probably a lot more than the const
optimizations Walter is talking about here.
Yes and the fact that D prohibits this incredibly common C++
design anti-pattern makes me very grateful about such choice.
Logical const is terrible - either don't mark such objects as
const or make cache separate.
+1
Use an interface that prevents external modifications, e.g.
getters, but no setters.
