On Wednesday, 11 July 2012 at 02:02:52 UTC, Andrei Alexandrescu
wrote:
On 7/10/12 9:45 PM, Timon Gehr wrote:
I do not desire logical const as a language feature. But
conservative
type systems are not good for everything. The root of the class
hierarchy needs to be good for everything. Object is not an
adequate
root any more.
How about we consider just stiffening that upper lip and
implement comparison and hashing without modifying their target?
Andrei
It's more likely to go down like this: programmer attempts to
write his opEquals (or toString etc) within the restrictions of
const, but fails due to the requirements of the implementation
(which can easily go beyond simple performance measures like
caching, as demonstrated). The programmer then writes his own
mutable member function and neglects opEquals altogether. If the
programmer is real nice, he/she will write a throwing opEquals
stub.
