Merge pull request #617 from lorentey/rigidly-enforced-lifetime-requirements

Fix lifetime requirements rigidly enforced in the latest nightlies

Author: lorentey

Sources/BasicContainers/RigidDictionary/RigidDictionary+Indices.swift

@@ -70,7 +70,7 @@ where Key: ~Copyable, Value: ~Copyable
   @inlinable
   public var underestimatedCount_: Int { self._base.value.count }
 
-  @_lifetime(copy self)
+  @_lifetime(borrow self) // FIXME: Should be @_lifetime(copy self)
   public func makeBorrowingIterator_() -> BorrowingIterator_ {
     let bit = self._base.value.makeBucketIterator()
     // FIXME: This override really should not be necessary. Check if the real `struct Borrow` fixes it.

Sources/BasicContainers/RigidSet/RigidSet+BorrowingSequence.swift

@@ -43,6 +43,8 @@ extension RigidSet: BorrowingSequence_ where Element: ~Copyable {
     ~Copyable,
     ~Escapable
   {
+    public typealias Element_ = Element
+
     @_alwaysEmitIntoClient
     internal var _baseAddress: UnsafePointer<Element_>?
 
@@ -68,7 +70,7 @@ extension RigidSet: BorrowingSequence_ where Element: ~Copyable {
     }
 
     @_alwaysEmitIntoClient
-    @_lifetime(copy self)
+    @_lifetime(&self) // FIXME: This should be `@_lifetime(copy self)`
     public mutating func nextSpan_(maximumCount: Int) -> Span<Element_> {
       precondition(maximumCount > 0, "maximumCount must be positive")
       guard

Sources/ContainersPreview/Protocols/Container/Container+Filter.swift

@@ -87,7 +87,9 @@ where Base.Element: ~Copyable
 
 @available(SwiftStdlib 5.0, *)
 extension ContainerFilter: BorrowingIteratorProtocol_ where Element: ~Copyable {
-  @_lifetime(copy self)
+  public typealias Element_ = Base.Element
+
+  @_lifetime(&self) // FIXME: This should be `@_lifetime(copy self)`
   public mutating func nextSpan_(maximumCount: Int) -> Span<Element> {
     precondition(maximumCount > 0)
     while true {

Sources/ContainersPreview/Protocols/Container/ContainerIterator.swift

@@ -52,23 +52,24 @@ where
 {
   public typealias Element_ = Base.Element
 
+#if true
   @_unsafeNonescapableResult // FIXME: we cannot convert from a borrow to an inout dependence?!
   @_lifetime(&self)
   public mutating func nextSpan_(maximumCount: Int) -> Span<Base.Element> {
     _base.value.nextSpan(after: &self._position, maximumCount: maximumCount)
   }
-
-//  @_lifetime(copy self)
-//  public mutating func nextSpan2(maximumCount: Int) -> Span<Base.Element> {
-//    var i = self._position
-//    let span = _base.value.nextSpan(
-//      after: &i,
-//      maximumCount: maximumCount)
-//    _ = consume span
-//    let result = _overrideLifetime(span, copying: self)
-//    self._position = i
-//    return .init()
-//  }
+#else
+  @_lifetime(copy self)
+  public mutating func nextSpan(maximumCount: Int) -> Span<Base.Element> {
+    var i = self._position
+    let span = _base.value.nextSpan(
+      after: &i,
+      maximumCount: maximumCount)
+    self._position = i
+    let result = _overrideLifetime(span, copying: self)
+    return result
+  }
+#endif
 
   @_lifetime(self: copy self)
   public mutating func skip_(by maximumOffset: Int) -> Int {

Sources/DequeModule/RigidDeque/RigidDeque+Container.swift

@@ -24,6 +24,8 @@ extension RigidDeque where Element: ~Copyable {
 #if compiler(>=6.4) && COLLECTIONS_UNSTABLE_CONTAINERS_PREVIEW
   @frozen
   public struct BorrowingIterator: ~Escapable, BorrowingIteratorProtocol_ {
+    public typealias Element_ = Element
+
     @usableFromInline
     internal var _currentSegment: Span<Element>
 
@@ -44,7 +46,7 @@ extension RigidDeque where Element: ~Copyable {
     }
 
     @_alwaysEmitIntoClient
-    @_lifetime(copy self)
+    @_lifetime(&self) // FIXME: This should be `@_lifetime(copy self)`
     @_lifetime(self: copy self)
     public mutating func nextSpan_(maximumCount: Int) -> Span<Element> {
       let result = _currentSegment._trim(first: maximumCount)

Tests/_CollectionsTestSupport/MinimalTypes/StaccatoContainer.swift

@@ -77,6 +77,8 @@ package struct _StaccatoParameters {
 
 @available(SwiftStdlib 5.0, *)
 public struct _StaccatoBorrowingIterator<Element: ~Copyable>: BorrowingIteratorProtocol_, ~Escapable {
+  public typealias Element_ = Element
+
   internal let _contents: Span<Element>
   internal let _params: _StaccatoParameters
   internal var _offset: Int
@@ -88,7 +90,7 @@ public struct _StaccatoBorrowingIterator<Element: ~Copyable>: BorrowingIteratorP
     self._offset = 0
   }
 
-  @_lifetime(copy self)
+  @_lifetime(&self) // FIXME: Should be `@_lifetime(copy self)`
   public mutating func nextSpan_(maximumCount: Int) -> Span<Element> {
     let endOffset = _params.endOffset(fromOffset: _offset, maximumCount: maximumCount)
     let startOffset = _offset