affects ABIgood first issueimprovementstandard libraryswift evolution proposal needed
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描述
| Previous ID | SR-3419 |
| Radar | rdar://problem/17816925 |
| Original Reporter | @airspeedswift |
| Type | Improvement |
| Votes | 0 |
| Component/s | Standard Library |
| Labels | Improvement, AffectsABI, StarterProposal, swift-evolution-proposal-needed |
| Assignee | None |
| Priority | Medium |
md5: 20684cd6a789b38a9426158bdf2d0b60
Issue Description:
In Swift 3.0, StrideTo and StrideThrough conform to Sequence, but not Collection.
While they can't be bi-directional or random-access, as the last (or abitrary) element can't necessarily be reached in O( n ) for all strideable types, it should be possible to make them forward-only collections. One straightforward implementation would be to make the index each value zipped with a count (for Comparable purposes).
Once we have conditional conformance, it should be possible to make specific strides (e.g. ones over integers) conform to random access.