On 2012-10-01 12:27 PM, Nathan Froyd wrote:
I recently filed a bug (bug 792169) for adding NS_NewIMutableArray, in service of deleting nsISupportsArray. The reviewer asked me to use more standard C++ instead of perpetuating the NS_New* idiom and I did so, with a static |Create| member function.However, looking through other code--especially the various bits under dom/ that have been added for B2G--I see that the NS_New* style is alive and well. Points for NS_New*: + Avoid exporting internal datastructures; + Possibly more efficient than do_CreateInstance and friends; - Usually requires %{C++ blocks in IDL files; - Less C++-y. Points for new and/or static member functions: + More C++-y; + Less function call overhead compared to NS_New* (modulo LTO); - Drags in more headers. ...and there are probably other things that I haven't thought of for both of them. So which style do we want to embrace? Or are there good reasons to continue with both?
There might be times where you want the concrete type of the thing that your ctor function returns to be opaque, in which case it might make sense to go with the NS_NewFoo style of method. But in all other cases I would prefer Foo::Create or something like that (or just new Foo, if you don't need to do fallible things in the ctor). Basically the more our code looks like C++, the better it is for people who have worked on other code bases.
Cheers, Ehsan _______________________________________________ dev-platform mailing list [email protected] https://lists.mozilla.org/listinfo/dev-platform
