[stdlib] use a primary associated type

Author: glessard

stdlib/public/core/UnsafeBufferPointer.swift.gyb

@@ -711,9 +711,9 @@ extension Unsafe${Mutable}BufferPointer {
   ///     by this function.
   @inlinable
   @_alwaysEmitIntoClient
-  public func initialize<C: Collection>(
-    fromContentsOf source: C
-  ) -> Index where C.Element == Element {
+  public func initialize(
+    fromContentsOf source: some Collection<Element>
+  ) -> Index {
     let count = source.withContiguousStorageIfAvailable {
       guard let sourceAddress = $0.baseAddress, !$0.isEmpty else {
         return 0
@@ -814,9 +814,9 @@ extension Unsafe${Mutable}BufferPointer {
   /// - Returns: An index one past the index of the last element updated.
   @inlinable
   @_alwaysEmitIntoClient
-  public func update<C: Collection>(
-    fromContentsOf source: C
-  ) -> Index where C.Element == Element {
+  public func update(
+    fromContentsOf source: some Collection<Element>
+  ) -> Index {
     let count = source.withContiguousStorageIfAvailable {
       guard let sourceAddress = $0.baseAddress else {
         return 0

stdlib/public/core/UnsafeBufferPointerSlice.swift

@@ -763,9 +763,9 @@ extension Slice {
   ///    initialized by this function.
   @inlinable
   @_alwaysEmitIntoClient
-  public func initialize<C: Collection>(
-    fromContentsOf source: C
-  ) -> Index where Base == UnsafeMutableBufferPointer<C.Element> {
+  public func initialize<Element>(
+    fromContentsOf source: some Collection<Element>
+  ) -> Index where Base == UnsafeMutableBufferPointer<Element> {
     let buffer = Base(rebasing: self)
     let index = buffer.initialize(fromContentsOf: source)
     let distance = buffer.distance(from: buffer.startIndex, to: index)
@@ -833,9 +833,9 @@ extension Slice {
   /// - Returns: An index one past the index of the last element updated.
   @inlinable
   @_alwaysEmitIntoClient
-  public func update<C: Collection>(
-    fromContentsOf source: C
-  ) -> Index where Base == UnsafeMutableBufferPointer<C.Element> {
+  public func update<Element>(
+    fromContentsOf source: some Collection<Element>
+  ) -> Index where Base == UnsafeMutableBufferPointer<Element> {
     let buffer = Base(rebasing: self)
     let index = buffer.update(fromContentsOf: source)
     let distance = buffer.distance(from: buffer.startIndex, to: index)