Merge remote-tracking branch 'origin/master' into master-next

Author: swift-ci

stdlib/public/core/ArrayCast.swift

@@ -28,7 +28,7 @@ internal func _arrayDownCastIndirect<SourceValue, TargetValue>(
 ///
 /// - Note: When SourceElement and TargetElement are both bridged verbatim, type
 ///   checking is deferred until elements are actually accessed.
-@inlinable // FIXME(sil-serialize-all)
+@inlinable //for performance reasons
 public func _arrayForceCast<SourceElement, TargetElement>(
   _ source: Array<SourceElement>
 ) -> Array<TargetElement> {
@@ -52,21 +52,6 @@ public func _arrayForceCast<SourceElement, TargetElement>(
   return source.map { $0 as! TargetElement }
 }
 
-@_fixed_layout
-@usableFromInline
-internal struct _UnwrappingFailed : Error {
-  @inlinable
-  internal init() {}
-}
-
-extension Optional {
-  @inlinable // FIXME(sil-serialize-all)
-  internal func unwrappedOrError() throws -> Wrapped {
-    if let x = self { return x }
-    throw _UnwrappingFailed()
-  }
-}
-
 /// Called by the casting machinery.
 @_silgen_name("_swift_arrayDownCastConditionalIndirect")
 internal func _arrayDownCastConditionalIndirect<SourceValue, TargetValue>(
@@ -85,9 +70,18 @@ internal func _arrayDownCastConditionalIndirect<SourceValue, TargetValue>(
 /// return `nil` if any element fails to convert.
 ///
 /// - Complexity: O(n), because each element must be checked.
-@inlinable // FIXME(sil-serialize-all)
+@inlinable //for performance reasons
 public func _arrayConditionalCast<SourceElement, TargetElement>(
   _ source: [SourceElement]
 ) -> [TargetElement]? {
-  return try? source.map { try ($0 as? TargetElement).unwrappedOrError() }
+  var successfulCasts = ContiguousArray<TargetElement>()
+  successfulCasts.reserveCapacity(source.count)
+  for element in source {
+    if let casted = element as? TargetElement {
+      successfulCasts.append(casted)
+    } else {
+      return nil
+    }
+  }
+  return Array(successfulCasts)
 }

test/api-digester/Outputs/stability-stdlib-abi.swift.expected

@@ -16,6 +16,9 @@ Func _int64ToStringImpl(_:_:_:_:_:) has been removed
 Func _uint64ToStringImpl(_:_:_:_:_:) has been removed
 Func _withUninitializedString(_:) has been removed
 
+Func Optional.unwrappedOrError() has been removed
+Struct _UnwrappingFailed has been removed
+
 Class _stdlib_AtomicInt has been removed
 Func _stdlib_atomicCompareExchangeStrongInt(object:expected:desired:) has been removed
 Func _stdlib_atomicCompareExchangeStrongInt32(object:expected:desired:) has been removed