On Thu, Jul 12, 2012 at 01:51:31PM -0400, Andrei Alexandrescu wrote: > On 7/12/12 1:40 PM, David Piepgrass wrote: > >1. Most importantly, the C++ template approach is a big pain for > >large-scale systems, [...] > > The thing is, that can be done in an opt-in manner. People who want > methods in the root of the hierarchy can define a root that defines > them. But there's no way to opt out of inheriting Object. Basically > it's nice to not force people to buy into a constrained environment > without necessity.
Having a class RawObject as a superclass of Object is an equally good solution. Declare a class without a base class, and the base class defaults to Object. Explicitly write "class MyClass : RawObject" and you get a class without the stuff in Object. If you want an entire hierarchy free of the stuff in Object, just write "class MyBaseClass : RawObject" and inherit everything from it. This has the advantage of _not_ breaking any existing code, and the people who want to opt out of Object, can. [...] > >1. Provide a 'safe workaround' for const, for caching and lazy > >evaluation (implement it carefully to avoid breaking the guarantees > >of immutable) > > We should explore this option in any case. At this point I'm > starting to believe (a) we're doing the right thing by marginalizing > the four methods aside from this issue, (b) caching is good for > other things than this particular problem. [...] Please also remember that caching is only _one_ of the issues. Objects that exist over the network is another use case. Objects that are partially stored in (possibly remote) database. There are many other such cases. I hope we don't neglect these other cases by focusing only on caching. T -- Why are you blatanly misspelling "blatant"? -- Branden Robinson
