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c47aea7150
When we see two type(aliase)s with the same name in a protocol hierarchy, make them equal with an implied same-type requirement. This detects inconstencies in typealiases across different protocols, and eliminates the need for ad hoc consistency checking. This is a step toward simplifying away the need for direct-diagnosis operations involving concrete type mismatches. While here, warn when we see an associated type with the same as a typealias from an inherited protocol; in this case, the associated type is basically useless, because it's going to be equivalent to the typealias.
30 lines
777 B
Swift
30 lines
777 B
Swift
// RUN: %target-swift-frontend %s -emit-ir
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struct MySlice<Base : MyIndexableType> : MyCollectionType {}
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struct MyMutableSlice<Base : MyMutableCollectionType> : MyMutableCollectionType {}
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protocol MySequenceType {}
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protocol MyIndexableType {}
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protocol MyCollectionType : MySequenceType, MyIndexableType {
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associatedtype SubSequence = MySlice<Self>
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func makeSubSequence() -> SubSequence
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}
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extension MyCollectionType {
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func makeSubSequence() -> MySlice<Self> {
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typealias S = Self
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return MySlice<S>()
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}
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}
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protocol MyMutableCollectionType : MyCollectionType {
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associatedtype SubSequence = MyMutableSlice<Self>
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}
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extension MyMutableCollectionType {
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func makeSubSequence() -> MyMutableSlice<Self> {
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typealias S = Self
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return MyMutableSlice<S>()
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}
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}
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