Le 20 janv. 2010 à 00:18, Kyle Sluder a écrit : > On Tue, Jan 19, 2010 at 3:09 PM, Shawn Rutledge > <shawn.t.rutle...@gmail.com> wrote: >> Well yeah, that's one of the reasons java.lang.String is immutable. >> But it helps that java.lang.Object has both hashCode and equals, so >> any object can be put into a collection that depends on those... you >> just have the option of improving the implementation of those for >> better hash distribution, comparing two objects by content rather than >> reference location, etc. I just wanted a hashtable that uses keys by >> pointer rather than expecting to copy them. Nice to know that copying >> protocol doesn't mean you have to actually copy it though. > > NSObject has -hash and -isEqual:. If you want a pointer-based > dictionary, create a CFDictionary with the appropriate options, and > cast it to NSDictionary* (read the documentation on Toll-Free Bridging > to see why this is possible).
An other solution can be to use NSMapTable class. I prefer it to CFDictionary because the later is not really toll-free bridged when using custom key/value callbacks. Even with a NULL or CFType Key callback, if you use NSMutableDictionary methods, is will try to copy the keys. >> As for C++, you can use template containers to store either pointers >> or copies of objects, whichever you like. > > STL containers are far more explicit about their internal behavior. > It's possible to write a collection class that has the same > restrictions as NSDictionary. > > --Kyle Sluder > _______________________________________________ > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/cocoa-dev/devlists%40shadowlab.org > > This email sent to devli...@shadowlab.org > -- Jean-Daniel _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
