[stdlib] Conditional gardening

Author: Max Moiseev

stdlib/public/core/Indices.swift

@@ -130,5 +130,7 @@ extension Collection where Indices == DefaultIndices<Self> {
   }
 }
 
-public typealias DefaultBidirectionalIndices<T: BidirectionalCollection> = DefaultIndices<T>
-public typealias DefaultRandomAccessIndices<T: RandomAccessCollection> = DefaultIndices<T>
+@available(*, deprecated, renamed: "DefaultIndices")
+public typealias DefaultBidirectionalIndices<T> = DefaultIndices<T> where T : BidirectionalCollection
+@available(*, deprecated, renamed: "DefaultIndices")
+public typealias DefaultRandomAccessIndices<T> = DefaultIndices<T> where T : RandomAccessCollection

stdlib/public/core/RangeReplaceableCollection.swift

@@ -70,9 +70,8 @@ public typealias RangeReplaceableIndexable = RangeReplaceableCollection
 /// `replaceSubrange(_:with:)` with an empty collection for the `newElements` 
 /// parameter. You can override any of the protocol's required methods to 
 /// provide your own custom implementation.
-public protocol RangeReplaceableCollection: Collection
-where SubSequence: RangeReplaceableCollection
-{
+public protocol RangeReplaceableCollection : Collection
+  where SubSequence : RangeReplaceableCollection {
   // FIXME(ABI): Associated type inference requires this.
   associatedtype SubSequence = Slice<Self>
 
@@ -782,9 +781,7 @@ extension RangeReplaceableCollection {
 }
 
 extension RangeReplaceableCollection
-  where
-  Self : BidirectionalCollection,
-  SubSequence == Self {
+  where Self : BidirectionalCollection, SubSequence == Self {
 
   @_inlineable
   public mutating func _customRemoveLast() -> Element? {
@@ -854,10 +851,7 @@ extension RangeReplaceableCollection where Self : BidirectionalCollection {
 // FIXME: swift-3-indexing-model: file a bug for the compiler?
 /// Ambiguity breakers.
 extension RangeReplaceableCollection
-  where
-  Self : BidirectionalCollection,
-  SubSequence == Self
-{
+  where Self : BidirectionalCollection, SubSequence == Self {
   /// Removes and returns the last element of the collection.
   ///
   /// The collection must not be empty.

stdlib/public/core/Slice.swift

@@ -264,7 +264,8 @@ extension Slice: MutableCollection where Base: MutableCollection {
 
 extension Slice: RandomAccessCollection where Base: RandomAccessCollection { }
 
-extension Slice: RangeReplaceableCollection where Base: RangeReplaceableCollection {
+extension Slice: RangeReplaceableCollection
+  where Base: RangeReplaceableCollection {
   @_inlineable // FIXME(sil-serialize-all)
   public init() {
     self._base = Base()
@@ -354,7 +355,7 @@ extension Slice: RangeReplaceableCollection where Base: RangeReplaceableCollecti
 }
 
 extension Slice
-where Base: RangeReplaceableCollection, Base: BidirectionalCollection {
+  where Base: RangeReplaceableCollection, Base: BidirectionalCollection {
 
   @_inlineable // FIXME(sil-serialize-all)
   public mutating func replaceSubrange<C>(
@@ -476,27 +477,25 @@ where Base: RangeReplaceableCollection, Base: BidirectionalCollection {
 }
 
 @available(*, deprecated, renamed: "Slice")
-public typealias BidirectionalSlice<T> = Slice<T> where T: BidirectionalCollection
+public typealias BidirectionalSlice<T> = Slice<T> where T : BidirectionalCollection
 @available(*, deprecated, renamed: "Slice")
-public typealias RandomAccessSlice<T> = Slice<T> where T: RandomAccessCollection
+public typealias RandomAccessSlice<T> = Slice<T> where T : RandomAccessCollection
 @available(*, deprecated, renamed: "Slice")
-public typealias RangeReplaceableSlice<T> = Slice<T> where T: RangeReplaceableCollection
+public typealias RangeReplaceableSlice<T> = Slice<T> where T : RangeReplaceableCollection
 @available(*, deprecated, renamed: "Slice")
-public typealias RangeReplaceableBidirectionalSlice<T> = Slice<T> where T: RangeReplaceableCollection, T: BidirectionalCollection
+public typealias RangeReplaceableBidirectionalSlice<T> = Slice<T> where T : RangeReplaceableCollection & BidirectionalCollection
 @available(*, deprecated, renamed: "Slice")
-public typealias RangeReplaceableRandomAccessSlice<T> = Slice<T> where T: RangeReplaceableCollection, T: RandomAccessCollection
+public typealias RangeReplaceableRandomAccessSlice<T> = Slice<T> where T : RangeReplaceableCollection & RandomAccessCollection
 
 @available(*, deprecated, renamed: "Slice")
-public typealias MutableSlice<T: MutableCollection> = Slice<T>
+public typealias MutableSlice<T> = Slice<T> where T : MutableCollection
 @available(*, deprecated, renamed: "Slice")
-public typealias MutableBidirectionalSlice<T: MutableCollection> = Slice<T> where T: BidirectionalCollection
+public typealias MutableBidirectionalSlice<T> = Slice<T> where T : MutableCollection & BidirectionalCollection
 @available(*, deprecated, renamed: "Slice")
-public typealias MutableRandomAccessSlice<T: MutableCollection> = Slice<T> where T: RandomAccessCollection
+public typealias MutableRandomAccessSlice<T> = Slice<T> where T : MutableCollection & RandomAccessCollection
 @available(*, deprecated, renamed: "Slice")
-public typealias MutableRangeReplaceableSlice<T: MutableCollection> = Slice<T> where T: RangeReplaceableCollection
+public typealias MutableRangeReplaceableSlice<T> = Slice<T> where T : MutableCollection & RangeReplaceableCollection
 @available(*, deprecated, renamed: "Slice")
-public typealias MutableRangeReplaceableBidirectionalSlice<T: MutableCollection> = Slice<T> where T: RangeReplaceableCollection, T: BidirectionalCollection
+public typealias MutableRangeReplaceableBidirectionalSlice<T> = Slice<T> where T : MutableCollection & RangeReplaceableCollection & BidirectionalCollection
 @available(*, deprecated, renamed: "Slice")
-public typealias MutableRangeReplaceableRandomAccessSlice<T: MutableCollection> = Slice<T> where T: RangeReplaceableCollection, T: RandomAccessCollection
-
-
+public typealias MutableRangeReplaceableRandomAccessSlice<T> = Slice<T> where T : MutableCollection & RangeReplaceableCollection & RandomAccessCollection

test/stdlib/collection-combinatorics.swift.gyb

@@ -66,6 +66,6 @@ struct ${indexLabel}${mutable}${rangeReplaceable}${capability}Butt
   // This type alias is required for some random-access collections with
   // a custom index type -- without it the default implementation for
   // `indices` doesn't attach.
-  typealias Indices = DefaultRandomAccessIndices<${indexLabel}${mutable}${rangeReplaceable}${capability}Butt>
+  typealias Indices = DefaultIndices<${indexLabel}${mutable}${rangeReplaceable}${capability}Butt>
 %         end
 }