Allow CustomStringConvertible et al: ~Copyable

Author: airspeedswift

stdlib/public/core/OutputStream.swift

@@ -99,7 +99,7 @@ extension TextOutputStream {
 /// To add `TextOutputStreamable` conformance to a custom type, implement the
 /// required `write(to:)` method. Call the given output stream's `write(_:)`
 /// method in your implementation.
-public protocol TextOutputStreamable {
+public protocol TextOutputStreamable: ~Copyable {
   /// Writes a textual representation of this instance into the given output
   /// stream.
   func write<Target: TextOutputStream>(to target: inout Target)
@@ -147,7 +147,7 @@ public protocol TextOutputStreamable {
 ///
 ///     print(p)
 ///     // Prints "(21, 30)"
-public protocol CustomStringConvertible {
+public protocol CustomStringConvertible: ~Copyable {
   /// A textual representation of this instance.
   ///
   /// Calling this property directly is discouraged. Instead, convert an
@@ -182,7 +182,7 @@ public protocol CustomStringConvertible {
 /// The description property of a conforming type must be a value-preserving
 /// representation of the original value. As such, it should be possible to
 /// re-create an instance from its string representation.
-public protocol LosslessStringConvertible: CustomStringConvertible {
+public protocol LosslessStringConvertible: CustomStringConvertible, ~Copyable {
   /// Instantiates an instance of the conforming type from a string
   /// representation.
   init?(_ description: String)
@@ -239,7 +239,7 @@ public protocol LosslessStringConvertible: CustomStringConvertible {
 ///
 ///     print(String(reflecting: p))
 ///     // Prints "(21, 30)"
-public protocol CustomDebugStringConvertible {
+public protocol CustomDebugStringConvertible: ~Copyable {
   /// A textual representation of this instance, suitable for debugging.
   ///
   /// Calling this property directly is discouraged. Instead, convert an

stdlib/public/core/StringInterpolation.swift

@@ -105,8 +105,9 @@ public struct DefaultStringInterpolation: StringInterpolationProtocol, Sendable
   ///     print(message)
   ///     // Prints "If one cookie costs 2 dollars, 3 cookies cost 6 dollars."
   @inlinable
-  public mutating func appendInterpolation<T>(_ value: T)
-    where T: TextOutputStreamable, T: CustomStringConvertible
+  @_preInverseGenerics
+  public mutating func appendInterpolation<T>(_ value: borrowing T)
+    where T: TextOutputStreamable, T: CustomStringConvertible, T: ~Copyable
   {
     value.write(to: &self)
   }
@@ -127,8 +128,9 @@ public struct DefaultStringInterpolation: StringInterpolationProtocol, Sendable
   ///     print(message)
   ///     // Prints "If one cookie costs 2 dollars, 3 cookies cost 6 dollars."
   @inlinable
-  public mutating func appendInterpolation<T>(_ value: T)
-    where T: TextOutputStreamable
+  @_preInverseGenerics
+  public mutating func appendInterpolation<T>(_ value: borrowing T)
+    where T: TextOutputStreamable & ~Copyable
   {
     value.write(to: &self)
   }
@@ -151,8 +153,9 @@ public struct DefaultStringInterpolation: StringInterpolationProtocol, Sendable
   ///     print(message)
   ///     // Prints "If one cookie costs 2 dollars, 3 cookies cost 6 dollars."
   @inlinable
-  public mutating func appendInterpolation<T>(_ value: T)
-    where T: CustomStringConvertible
+  @_preInverseGenerics
+  public mutating func appendInterpolation<T>(_ value: borrowing T)
+    where T: CustomStringConvertible, T: ~Copyable
   {
     value.description.write(to: &self)
   }
@@ -175,7 +178,7 @@ public struct DefaultStringInterpolation: StringInterpolationProtocol, Sendable
   ///     print(message)
   ///     // Prints "If one cookie costs 2 dollars, 3 cookies cost 6 dollars."
   @inlinable
-  public mutating func appendInterpolation<T>(_ value: T) {
+  public mutating func appendInterpolation<T>(_ value: borrowing T) {
     #if !$Embedded
     _print_unlocked(value, &self)
     #else
@@ -217,13 +220,15 @@ extension DefaultStringInterpolation {
   ///   - value: The value to include in a string interpolation, if non-`nil`.
   ///   - default: The string to include if `value` is `nil`.
   @_alwaysEmitIntoClient
+  @_preInverseGenerics
   public mutating func appendInterpolation<T>(
-    _ value: T?,
+    _ value: borrowing T?,
     default: @autoclosure () -> some StringProtocol
-  ) where T: TextOutputStreamable, T: CustomStringConvertible {
-    if let value {
+  ) where T: TextOutputStreamable, T: CustomStringConvertible, T: ~Copyable {
+    switch value {
+    case let value?:
       self.appendInterpolation(value)
-    } else {
+    case nil:
       self.appendInterpolation(`default`())
     }
   }
@@ -247,13 +252,15 @@ extension DefaultStringInterpolation {
   ///   - value: The value to include in a string interpolation, if non-`nil`.
   ///   - default: The string to include if `value` is `nil`.
   @_alwaysEmitIntoClient
+  @_preInverseGenerics
   public mutating func appendInterpolation<T>(
-    _ value: T?,
+    _ value: borrowing T?,
     default: @autoclosure () -> some StringProtocol
-  ) where T: TextOutputStreamable {
-    if let value {
+  ) where T: TextOutputStreamable & ~Copyable {
+    switch value {
+    case let value?:
       self.appendInterpolation(value)
-    } else {
+    case nil:
       self.appendInterpolation(`default`())
     }
   }
@@ -277,13 +284,15 @@ extension DefaultStringInterpolation {
   ///   - value: The value to include in a string interpolation, if non-`nil`.
   ///   - default: The string to include if `value` is `nil`.
   @_alwaysEmitIntoClient
+  @_preInverseGenerics
   public mutating func appendInterpolation<T>(
-    _ value: T?, 
+    _ value: borrowing T?, 
     default: @autoclosure () -> some StringProtocol
-  ) where T: CustomStringConvertible {
-    if let value {
+  ) where T: CustomStringConvertible, T: ~Copyable {
+    switch value {
+    case let value?:
       self.appendInterpolation(value)
-    } else {
+    case nil:
       self.appendInterpolation(`default`())
     }
   }
@@ -311,9 +320,10 @@ extension DefaultStringInterpolation {
     _ value: T?, 
     default: @autoclosure () -> some StringProtocol
   ) {
-    if let value {
+    switch value {
+    case let value?:
       self.appendInterpolation(value)
-    } else {
+    case nil:
       self.appendInterpolation(`default`())
     }
   }

test/Generics/inverse_copyable_requirement.swift

@@ -232,7 +232,7 @@ func checkCasting(_ b: any Box, _ mo: borrowing MO, _ a: Any) {
 // the stdlib right now is not yet being compiled with NoncopyableGenerics
 func checkStdlibTypes(_ mo: borrowing MO) {
   _ = "\(mo)" // expected-error {{no exact matches in call to instance method 'appendInterpolation'}}
-  let _: String = String(describing: mo) // expected-error {{no exact matches in call to initializer}}
+  let _: String = String(describing: mo) // expected-error {{initializer 'init(describing:)' requires that 'MO' conform to 'Copyable'}}
 
   let _: [MO] = // expected-error {{type 'MO' does not conform to protocol 'Copyable'}}
       [MO(), MO()]

test/api-digester/Outputs/stability-stdlib-source-base.swift.expected

@@ -53,6 +53,7 @@ Constructor ContiguousArray.init(unsafeUninitializedCapacity:initializingWith:)
 Constructor ContiguousArray.init(unsafeUninitializedCapacity:initializingWith:) has parameter 1 type change from (inout Swift.UnsafeMutableBufferPointer<Element>, inout Swift.Int) throws -> Swift.Void to (inout Swift.UnsafeMutableBufferPointer<Element>, inout Swift.Int) throws(E) -> Swift.Void
 Constructor ContiguousArray.init(unsafeUninitializedCapacity:initializingWith:) is now without rethrows
 
+Protocol LosslessStringConvertible has generic signature change from <Self : Swift.CustomStringConvertible> to <Self : Swift.CustomStringConvertible, Self : ~Copyable>
 Protocol SIMDScalar has generic signature change from <Self == Self.SIMD16Storage.Scalar, Self.SIMD16Storage : Swift.SIMDStorage, Self.SIMD2Storage : Swift.SIMDStorage, Self.SIMD32Storage : Swift.SIMDStorage, Self.SIMD4Storage : Swift.SIMDStorage, Self.SIMD64Storage : Swift.SIMDStorage, Self.SIMD8Storage : Swift.SIMDStorage, Self.SIMDMaskScalar : Swift.FixedWidthInteger, Self.SIMDMaskScalar : Swift.SIMDScalar, Self.SIMDMaskScalar : Swift.SignedInteger, Self.SIMD16Storage.Scalar == Self.SIMD2Storage.Scalar, Self.SIMD2Storage.Scalar == Self.SIMD32Storage.Scalar, Self.SIMD32Storage.Scalar == Self.SIMD4Storage.Scalar, Self.SIMD4Storage.Scalar == Self.SIMD64Storage.Scalar, Self.SIMD64Storage.Scalar == Self.SIMD8Storage.Scalar> to <Self : Swift.BitwiseCopyable, Self == Self.SIMD16Storage.Scalar, Self.SIMD16Storage : Swift.SIMDStorage, Self.SIMD2Storage : Swift.SIMDStorage, Self.SIMD32Storage : Swift.SIMDStorage, Self.SIMD4Storage : Swift.SIMDStorage, Self.SIMD64Storage : Swift.SIMDStorage, Self.SIMD8Storage : Swift.SIMDStorage, Self.SIMDMaskScalar : Swift.FixedWidthInteger, Self.SIMDMaskScalar : Swift.SIMDScalar, Self.SIMDMaskScalar : Swift.SignedInteger, Self.SIMDMaskScalar == Self.SIMDMaskScalar.SIMDMaskScalar, Self.SIMD16Storage.Scalar == Self.SIMD2Storage.Scalar, Self.SIMD2Storage.Scalar == Self.SIMD32Storage.Scalar, Self.SIMD32Storage.Scalar == Self.SIMD4Storage.Scalar, Self.SIMD4Storage.Scalar == Self.SIMD64Storage.Scalar, Self.SIMD64Storage.Scalar == Self.SIMD8Storage.Scalar>
 
 Protocol AdditiveArithmetic has added inherited protocol Copyable
@@ -73,15 +74,13 @@ Protocol Collection has added inherited protocol Copyable
 Protocol Collection has added inherited protocol Escapable
 Protocol Comparable has added inherited protocol Escapable
 Protocol Comparable has generic signature change from <Self : Swift.Equatable> to <Self : Swift.Equatable, Self : ~Copyable>
-Protocol CustomDebugStringConvertible has added inherited protocol Copyable
 Protocol CustomDebugStringConvertible has added inherited protocol Escapable
 Protocol CustomLeafReflectable has added inherited protocol Copyable
 Protocol CustomLeafReflectable has added inherited protocol Escapable
 Protocol CustomPlaygroundDisplayConvertible has added inherited protocol Copyable
 Protocol CustomPlaygroundDisplayConvertible has added inherited protocol Escapable
 Protocol CustomReflectable has added inherited protocol Copyable
 Protocol CustomReflectable has added inherited protocol Escapable
-Protocol CustomStringConvertible has added inherited protocol Copyable
 Protocol CustomStringConvertible has added inherited protocol Escapable
 Protocol Decodable has added inherited protocol Copyable
 Protocol Decodable has added inherited protocol Escapable
@@ -130,7 +129,6 @@ Protocol LazyCollectionProtocol has added inherited protocol Copyable
 Protocol LazyCollectionProtocol has added inherited protocol Escapable
 Protocol LazySequenceProtocol has added inherited protocol Copyable
 Protocol LazySequenceProtocol has added inherited protocol Escapable
-Protocol LosslessStringConvertible has added inherited protocol Copyable
 Protocol LosslessStringConvertible has added inherited protocol Escapable
 Protocol MirrorPath has added inherited protocol Copyable
 Protocol MirrorPath has added inherited protocol Escapable
@@ -177,7 +175,6 @@ Protocol StringProtocol has added inherited protocol Copyable
 Protocol StringProtocol has added inherited protocol Escapable
 Protocol TextOutputStream has added inherited protocol Copyable
 Protocol TextOutputStream has added inherited protocol Escapable
-Protocol TextOutputStreamable has added inherited protocol Copyable
 Protocol TextOutputStreamable has added inherited protocol Escapable
 Protocol UnicodeCodec has added inherited protocol Copyable
 Protocol UnicodeCodec has added inherited protocol Escapable
@@ -190,6 +187,8 @@ Protocol UnsignedInteger has added inherited protocol Escapable
 Protocol _AppendKeyPath has added inherited protocol Copyable
 Protocol _AppendKeyPath has added inherited protocol Escapable
 
+Accessor CustomDebugStringConvertible.debugDescription.Get() has generic signature change from <Self where Self : Swift.CustomDebugStringConvertible> to <Self where Self : Swift.CustomDebugStringConvertible, Self : ~Copyable>
+Accessor CustomStringConvertible.description.Get() has generic signature change from <Self where Self : Swift.CustomStringConvertible> to <Self where Self : Swift.CustomStringConvertible, Self : ~Copyable>
 Accessor ManagedBuffer.capacity.Get() has generic signature change from <Header, Element> to <Header, Element where Element : ~Copyable>
 Accessor ManagedBuffer.header.Get() has generic signature change from <Header, Element> to <Header, Element where Element : ~Copyable>
 Accessor ManagedBuffer.header.Set() has generic signature change from <Header, Element> to <Header, Element where Element : ~Copyable>
@@ -217,6 +216,7 @@ Accessor UnsafePointer.hashValue.Get() has generic signature change from <Pointe
 Accessor UnsafePointer.pointee.Get() has been removed
 Accessor UnsafePointer.subscript(_:).Get() has been removed
 Class ManagedBuffer has generic signature change from <Header, Element> to <Header, Element where Element : ~Copyable>
+Constructor LosslessStringConvertible.init(_:) has generic signature change from <Self where Self : Swift.LosslessStringConvertible> to <Self where Self : Swift.LosslessStringConvertible, Self : ~Copyable>
 Constructor ExpressibleByNilLiteral.init(nilLiteral:) has generic signature change from <Self where Self : Swift.ExpressibleByNilLiteral> to <Self where Self : Swift.ExpressibleByNilLiteral, Self : ~Copyable, Self : ~Escapable>
 Constructor ManagedBufferPointer.init(bufferClass:minimumCapacity:makingHeaderWith:) has generic signature change from <Header, Element> to <Header, Element where Element : ~Copyable>
 Constructor ManagedBufferPointer.init(unsafeBufferObject:) has generic signature change from <Header, Element> to <Header, Element where Element : ~Copyable>
@@ -336,6 +336,10 @@ TypeAlias UnsafePointer.Stride has generic signature change from <Pointee> to <P
 Func FixedWidthInteger.&*(_:_:) has been added as a protocol requirement
 Accessor UnsafeBufferPointer.debugDescription.Get() has generic signature change from <Element> to <Element where Element : ~Copyable>
 Accessor UnsafeMutableBufferPointer.debugDescription.Get() has generic signature change from <Element> to <Element where Element : ~Copyable>
+Func DefaultStringInterpolation.appendInterpolation(_:) has generic signature change from <T where T : Swift.CustomStringConvertible, T : Swift.TextOutputStreamable> to <T where T : Swift.CustomStringConvertible, T : Swift.TextOutputStreamable, T : ~Copyable>
+Func DefaultStringInterpolation.appendInterpolation(_:) has generic signature change from <T where T : Swift.CustomStringConvertible> to <T where T : Swift.CustomStringConvertible, T : ~Copyable>
+Func DefaultStringInterpolation.appendInterpolation(_:) has generic signature change from <T where T : Swift.TextOutputStreamable> to <T where T : Swift.TextOutputStreamable, T : ~Copyable>
+Func DefaultStringInterpolation.appendInterpolation(_:) has parameter 0 changing from Default to Shared
 Func ManagedBuffer.withUnsafeMutablePointerToElements(_:) has generic signature change from <Header, Element, R> to <Header, Element, E, R where E : Swift.Error, Element : ~Copyable, R : ~Copyable>
 Func ManagedBuffer.withUnsafeMutablePointerToElements(_:) is now without rethrows
 Func ManagedBuffer.withUnsafeMutablePointerToHeader(_:) has generic signature change from <Header, Element, R> to <Header, Element, E, R where E : Swift.Error, Element : ~Copyable, R : ~Copyable>
@@ -358,6 +362,7 @@ Func Result.flatMapError(_:) has generic signature change from <Success, Failure
 Func Result.flatMapError(_:) has self access kind changing from NonMutating to Consuming
 Func Result.map(_:) has generic signature change from <Success, Failure, NewSuccess where Failure : Swift.Error> to <Success, Failure, NewSuccess where Failure : Swift.Error, NewSuccess : ~Copyable>
 Func Result.mapError(_:) has generic signature change from <Success, Failure, NewFailure where Failure : Swift.Error, NewFailure : Swift.Error> to <Success, Failure, NewFailure where Failure : Swift.Error, NewFailure : Swift.Error, Success : ~Copyable, Success : ~Escapable>
+Func TextOutputStreamable.write(to:) has generic signature change from <Self, Target where Self : Swift.TextOutputStreamable, Target : Swift.TextOutputStream> to <Self, Target where Self : Swift.TextOutputStreamable, Target : Swift.TextOutputStream, Self : ~Copyable>
 Func UnsafeBufferPointer.withMemoryRebound(to:_:) has generic signature change from <Element, T, Result> to <Element, T, E, Result where E : Swift.Error, Element : ~Copyable, T : ~Copyable, Result : ~Copyable>
 Func UnsafeBufferPointer.withMemoryRebound(to:_:) is now without rethrows
 Func UnsafeMutableBufferPointer.withMemoryRebound(to:_:) has generic signature change from <Element, T, Result> to <Element, T, E, Result where E : Swift.Error, Element : ~Copyable, T : ~Copyable, Result : ~Copyable>