On Fri, Apr 29, 2016 at 12:25 AM, David Hart via swift-evolution <swift-evolution@swift.org> wrote: > I’ve taken some time to digest the current feedback and I’ve changed my mind. > The syntax for adding constraints to a sub-protocol in the protocol’s > definition where clause is starting to grow on me. Before I modify the > proposal, I'd still like to understand something: > > What is the use of declaring a default associated types with the `=` syntax > in protocols? I’ve never used them and I don’t understand what they provide.
Please take a look at the Collection protocol (https://github.com/apple/swift/blob/master/stdlib/public/core/Collection.swift). associatedtype Iterator : IteratorProtocol = IndexingIterator<Self> associatedtype SubSequence : IndexableBase, Sequence = Slice<Self> associatedtype Indices : IndexableBase, Sequence = DefaultIndices<Self> Some collections want to customize these, but for simple ones the defaults are usually fine. Dmitri -- main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if (j){printf("%d\n",i);}}} /*Dmitri Gribenko <griboz...@gmail.com>*/ _______________________________________________ swift-evolution mailing list swift-evolution@swift.org https://lists.swift.org/mailman/listinfo/swift-evolution
