Restore concrete initializers on Unsafe{Raw}Pointer

Author: airspeedswift

stdlib/public/core/BridgeObjectiveC.swift

@@ -419,6 +419,35 @@ public struct AutoreleasingUnsafeMutablePointer<Pointee /* TODO : class */>
     }
   }
 
+  /// Explicit construction from an UnsafeMutablePointer.		
+  ///		
+  /// This is inherently unsafe; UnsafeMutablePointer assumes the		
+  /// referenced memory has +1 strong ownership semantics, whereas		
+  /// AutoreleasingUnsafeMutablePointer implies +0 semantics.		
+  ///		
+  /// - Warning: Accessing `pointee` as a type that is unrelated to		
+  ///   the underlying memory's bound type is undefined.		
+  @_transparent		
+  public init<U>(_ from: UnsafeMutablePointer<U>) {		
+   self._rawValue = from._rawValue		
+  }		
+
+  /// Explicit construction from an UnsafeMutablePointer.		
+  ///		
+  /// Returns nil if `from` is nil.		
+  ///		
+  /// This is inherently unsafe; UnsafeMutablePointer assumes the		
+  /// referenced memory has +1 strong ownership semantics, whereas		
+  /// AutoreleasingUnsafeMutablePointer implies +0 semantics.		
+  ///		
+  /// - Warning: Accessing `pointee` as a type that is unrelated to		
+  ///   the underlying memory's bound type is undefined.		
+  @_transparent		
+  public init?<U>(_ from: UnsafeMutablePointer<U>?) {		
+   guard let unwrapped = from else { return nil }		
+   self.init(unwrapped)		
+  }
+     
   /// Explicit construction from a UnsafePointer.
   ///
   /// This is inherently unsafe because UnsafePointers do not imply

stdlib/public/core/UnsafePointer.swift

@@ -544,6 +544,27 @@ public struct UnsafeMutablePointer<Pointee>: _Pointer {
     guard let unwrapped = other else { return nil }
     self.init(mutating: unwrapped)
   }
+  
+  /// Creates an immutable typed pointer referencing the same memory as the		
+  /// given mutable pointer.		
+  ///		
+  /// - Parameter other: The pointer to convert.		
+  @_transparent		
+  public init(_ other: UnsafeMutablePointer<Pointee>) {		
+   self._rawValue = other._rawValue		
+  }		
+
+  /// Creates an immutable typed pointer referencing the same memory as the		
+  /// given mutable pointer.		
+  ///		
+  /// - Parameter other: The pointer to convert. If `other` is `nil`, the		
+  ///   result is `nil`.		
+  @_transparent		
+  public init?(_ other: UnsafeMutablePointer<Pointee>?) {		
+   guard let unwrapped = other else { return nil }		
+   self.init(unwrapped)		
+  }		
+  
 
   /// Allocates uninitialized memory for the specified number of instances of
   /// type `Pointee`.

stdlib/public/core/UnsafeRawPointer.swift

@@ -235,6 +235,32 @@ public struct UnsafeRawPointer: _Pointer {
     _rawValue = unwrapped._rawValue
   }
 
+  /// Creates a new raw pointer from the given typed pointer.		
+  ///		
+  /// Use this initializer to explicitly convert `other` to an `UnsafeRawPointer`		
+  /// instance. This initializer creates a new pointer to the same address as		
+  /// `other` and performs no allocation or copying.		
+  ///		
+  /// - Parameter other: The typed pointer to convert.		
+  @_transparent		
+  public init<T>(_ other: UnsafeMutablePointer<T>) {		
+   _rawValue = other._rawValue		
+  }		
+
+  /// Creates a new raw pointer from the given typed pointer.		
+  ///		
+  /// Use this initializer to explicitly convert `other` to an `UnsafeRawPointer`		
+  /// instance. This initializer creates a new pointer to the same address as		
+  /// `other` and performs no allocation or copying.		
+  ///		
+  /// - Parameter other: The typed pointer to convert. If `other` is `nil`, the		
+  ///   result is `nil`.		
+  @_transparent		
+  public init?<T>(_ other: UnsafeMutablePointer<T>?) {		
+   guard let unwrapped = other else { return nil }		
+   _rawValue = unwrapped._rawValue		
+  }		
+
   /// Deallocates the previously allocated memory block referenced by this pointer.
   ///
   /// The memory to be deallocated must be uninitialized or initialized to a

test/stdlib/UnsafePointerDiagnostics.swift

@@ -61,8 +61,8 @@ func unsafePointerConversionAvailability(
   _ = UnsafeMutablePointer<Int>(umpi)
   _ = UnsafeMutablePointer<Int>(oumpi)
 
-  _ = UnsafeMutablePointer<Void>(rp) // expected-warning 4 {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}} expected-error {{cannot convert value of type 'UnsafeRawPointer' to expected argument type 'RawPointer'}}
-  _ = UnsafeMutablePointer<Void>(mrp) // expected-error {{cannot convert value of type 'UnsafeMutableRawPointer' to expected argument type 'RawPointer'}} expected-warning 4 {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}
+  _ = UnsafeMutablePointer<Void>(rp) // expected-warning 4 {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}} expected-error {{cannot invoke initializer for type 'UnsafeMutablePointer<Void>' with an argument list of type '(UnsafeRawPointer)'}} expected-note {{overloads for 'UnsafeMutablePointer<Void>' exist with these partially matching parameter lists: (RawPointer), (UnsafeMutablePointer<Pointee>), (UnsafeMutablePointer<Pointee>?)}} expected-note {{Pointer conversion restricted: use '.assumingMemoryBound(to:)' or '.bindMemory(to:capacity:)' to view memory as a type.}}
+  _ = UnsafeMutablePointer<Void>(mrp) // expected-warning 4 {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}} expected-error {{cannot invoke initializer for type 'UnsafeMutablePointer<Void>' with an argument list of type '(UnsafeMutableRawPointer)'}} expected-note {{overloads for 'UnsafeMutablePointer<Void>' exist with these partially matching parameter lists: (RawPointer), (UnsafeMutablePointer<Pointee>), (UnsafeMutablePointer<Pointee>?)}} expected-note {{Pointer conversion restricted: use '.assumingMemoryBound(to:)' or '.bindMemory(to:capacity:)' to view memory as a type.}}
   _ = UnsafeMutablePointer<Void>(umpv) // expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}
   _ = UnsafeMutablePointer<Void>(umpi) // expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}
   _ = UnsafeMutablePointer<Void>(umps) // expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}
@@ -76,10 +76,10 @@ func unsafePointerConversionAvailability(
   _ = UnsafePointer<Void>(umps) // expected-warning {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}}
   _ = UnsafePointer<Void>(ups) // expected-warning {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}}
 
-  _ = UnsafeMutablePointer<Int>(rp) // expected-error {{cannot convert value of type 'UnsafeRawPointer' to expected argument type 'RawPointer'}} 
-  _ = UnsafeMutablePointer<Int>(mrp) // expected-error {{cannot convert value of type 'UnsafeMutableRawPointer' to expected argument type 'RawPointer'}} 
-  _ = UnsafeMutablePointer<Int>(orp) // expected-error {{cannot convert value of type 'UnsafeRawPointer?' to expected argument type 'RawPointer'}}
-  _ = UnsafeMutablePointer<Int>(omrp) // expected-error {{cannot convert value of type 'UnsafeMutableRawPointer?' to expected argument type 'RawPointer'}} 
+  _ = UnsafeMutablePointer<Int>(rp) // expected-error {{cannot invoke initializer for type 'UnsafeMutablePointer<Int>' with an argument list of type '(UnsafeRawPointer)'}} expected-note {{overloads for 'UnsafeMutablePointer<Int>' exist with these partially matching parameter lists: (RawPointer), (UnsafeMutablePointer<Pointee>), (UnsafeMutablePointer<Pointee>?)}} expected-note {{Pointer conversion restricted: use '.assumingMemoryBound(to:)' or '.bindMemory(to:capacity:)' to view memory as a type.}}
+  _ = UnsafeMutablePointer<Int>(mrp) // expected-error {{cannot invoke initializer for type 'UnsafeMutablePointer<Int>' with an argument list of type '(UnsafeMutableRawPointer)'}} expected-note {{Pointer conversion restricted: use '.assumingMemoryBound(to:)' or '.bindMemory(to:capacity:)' to view memory as a type.}} expected-note {{overloads for 'UnsafeMutablePointer<Int>' exist with these partially matching parameter lists: (RawPointer), (UnsafeMutablePointer<Pointee>), (UnsafeMutablePointer<Pointee>?)}}
+  _ = UnsafeMutablePointer<Int>(orp) // expected-error {{cannot invoke initializer for type 'UnsafeMutablePointer<Int>' with an argument list of type '(UnsafeRawPointer?)'}} expected-note {{overloads for 'UnsafeMutablePointer<Int>' exist with these partially matching parameter lists: (RawPointer), (UnsafeMutablePointer<Pointee>), (UnsafeMutablePointer<Pointee>?)}} expected-note {{Pointer conversion restricted: use '.assumingMemoryBound(to:)' or '.bindMemory(to:capacity:)' to view memory as a type.}}
+  _ = UnsafeMutablePointer<Int>(omrp) // expected-error {{cannot invoke initializer for type 'UnsafeMutablePointer<Int>' with an argument list of type '(UnsafeMutableRawPointer?)'}} expected-note {{overloads for 'UnsafeMutablePointer<Int>' exist with these partially matching parameter lists: (RawPointer), (UnsafeMutablePointer<Pointee>), (UnsafeMutablePointer<Pointee>?)}} expected-note {{Pointer conversion restricted: use '.assumingMemoryBound(to:)' or '.bindMemory(to:capacity:)' to view memory as a type.}} 
 
   _ = UnsafePointer<Int>(rp)  // expected-error {{cannot convert value of type 'UnsafeRawPointer' to expected argument type 'RawPointer'}}
   _ = UnsafePointer<Int>(mrp) // expected-error {{cannot convert value of type 'UnsafeMutableRawPointer' to expected argument type 'RawPointer'}}
@@ -114,4 +114,4 @@ func unsafeRawBufferPointerConversions(
   _ = UnsafeRawBufferPointer(start: omrp, count: 1)
   _ = UnsafeMutableRawBufferPointer(start: orp, count: 1) // expected-error {{cannot convert value of type 'UnsafeRawPointer?' to expected argument type 'UnsafeMutableRawPointer?'}}
   _ = UnsafeRawBufferPointer(start: orp, count: 1)
-}
+}