Allow Comparable: ~Copyable

Author: airspeedswift

stdlib/public/core/Comparable.swift

@@ -135,7 +135,7 @@
 ///   (`FloatingPoint.nan`) compares as neither less than, greater than, nor
 ///   equal to any normal floating-point value. Exceptional values need not
 ///   take part in the strict total order.
-public protocol Comparable: Equatable {
+public protocol Comparable: Equatable, ~Copyable {
   /// Returns a Boolean value indicating whether the value of the first
   /// argument is less than that of the second argument.
   ///
@@ -146,34 +146,34 @@ public protocol Comparable: Equatable {
   /// - Parameters:
   ///   - lhs: A value to compare.
   ///   - rhs: Another value to compare.
-  static func < (lhs: Self, rhs: Self) -> Bool
+  static func < (lhs: borrowing Self, rhs: borrowing Self) -> Bool
 
   /// Returns a Boolean value indicating whether the value of the first
   /// argument is less than or equal to that of the second argument.
   ///
   /// - Parameters:
   ///   - lhs: A value to compare.
   ///   - rhs: Another value to compare.
-  static func <= (lhs: Self, rhs: Self) -> Bool
+  static func <= (lhs: borrowing Self, rhs: borrowing Self) -> Bool
 
   /// Returns a Boolean value indicating whether the value of the first
   /// argument is greater than or equal to that of the second argument.
   ///
   /// - Parameters:
   ///   - lhs: A value to compare.
   ///   - rhs: Another value to compare.
-  static func >= (lhs: Self, rhs: Self) -> Bool
+  static func >= (lhs: borrowing Self, rhs: borrowing Self) -> Bool
 
   /// Returns a Boolean value indicating whether the value of the first
   /// argument is greater than that of the second argument.
   ///
   /// - Parameters:
   ///   - lhs: A value to compare.
   ///   - rhs: Another value to compare.
-  static func > (lhs: Self, rhs: Self) -> Bool
+  static func > (lhs: borrowing Self, rhs: borrowing Self) -> Bool
 }
 
-extension Comparable {
+extension Comparable where Self: ~Copyable {
   /// Returns a Boolean value indicating whether the value of the first argument
   /// is greater than that of the second argument.
   ///
@@ -184,7 +184,8 @@ extension Comparable {
   ///   - lhs: A value to compare.
   ///   - rhs: Another value to compare.
   @inlinable
-  public static func > (lhs: Self, rhs: Self) -> Bool {
+  @_preInverseGenerics
+  public static func > (lhs: borrowing Self, rhs: borrowing Self) -> Bool {
     return rhs < lhs
   }
 
@@ -198,7 +199,8 @@ extension Comparable {
   ///   - lhs: A value to compare.
   ///   - rhs: Another value to compare.
   @inlinable
-  public static func <= (lhs: Self, rhs: Self) -> Bool {
+  @_preInverseGenerics
+  public static func <= (lhs: borrowing Self, rhs: borrowing Self) -> Bool {
     return !(rhs < lhs)
   }
 
@@ -214,7 +216,8 @@ extension Comparable {
   /// - Returns: `true` if `lhs` is greater than or equal to `rhs`; otherwise,
   ///   `false`.
   @inlinable
-  public static func >= (lhs: Self, rhs: Self) -> Bool {
+  @_preInverseGenerics
+  public static func >= (lhs: borrowing Self, rhs: borrowing Self) -> Bool {
     return !(lhs < rhs)
   }
 }

test/Constraints/diagnostics.swift

@@ -1470,14 +1470,12 @@ func testUnwrapFixIts(x: Int?) throws {
   // expected-note@-2 {{force-unwrap using '!' to abort execution if the optional value contains 'nil'}} {{11-11=!}}
   foo(y: x ?? 0) 
 
-  let _ = x < 2 // expected-error {{value of optional type 'Int?' must be unwrapped to a value of type 'Int'}}
-  // expected-note@-1 {{coalesce using '??' to provide a default when the optional value contains 'nil'}} {{12-12= ?? <#default value#>}}
-  // expected-note@-2 {{force-unwrap using '!' to abort execution if the optional value contains 'nil'}} {{12-12=!}}
+  let _ = x < 2 // expected-error {{binary operator '<' cannot be applied to operands of type 'Int?' and 'Int'}}
+  // expected-note@-1 {{overloads for '<' exist with these partially matching parameter lists: (Int, Int)}}
   let _ = x ?? 0 < 2
 
-  let _ = 2 < x // expected-error {{value of optional type 'Int?' must be unwrapped to a value of type 'Int'}}
-  // expected-note@-1 {{coalesce using '??' to provide a default when the optional value contains 'nil'}} {{16-16= ?? <#default value#>}}
-  // expected-note@-2 {{force-unwrap using '!' to abort execution if the optional value contains 'nil'}} {{16-16=!}}
+  let _ = 2 < x // expected-error {{binary operator '<' cannot be applied to operands of type 'Int' and 'Int?'}}
+  // expected-note@-1 {{overloads for '<' exist with these partially matching parameter lists: (Int, Int)}}
   let _ = 2 < x ?? 0
 
   let _: Int = (.optionalIntMember) // expected-error {{value of optional type 'Int?' must be unwrapped to a value of type 'Int'}}
@@ -1495,9 +1493,8 @@ func testUnwrapFixIts(x: Int?) throws {
   // expected-note@-2 {{force-unwrap using '!' to abort execution if the optional value contains 'nil'}} {{36-36=!}}
   let _ = try (.optionalThrowsMember ?? 0) + 1
 
-  let _ = .optionalIntMember?.bitWidth > 0 // expected-error {{value of optional type 'Int?' must be unwrapped to a value of type 'Int'}}
-  // expected-note@-1 {{coalesce using '??' to provide a default when the optional value contains 'nil'}} {{39-39= ?? <#default value#>}}
-  // expected-note@-2 {{force-unwrap using '!' to abort execution if the optional value contains 'nil'}} {{11-11=(}} {{39-39=)!}}
+  let _ = .optionalIntMember?.bitWidth > 0 // expected-error {{binary operator '>' cannot be applied to operands of type 'Int?' and 'Int'}}
+  // expected-note@-1 {{overloads for '>' exist with these partially matching parameter lists: (Int, Int)}}
   let _ = (.optionalIntMember?.bitWidth)! > 0
   let _ = .optionalIntMember?.bitWidth ?? 0 > 0
 

test/SILOptimizer/mandatory_performance_optimizations.sil

@@ -84,7 +84,7 @@ bb0:
 sil [no_allocation] [ossa] @deserialize_and_inline_after_devirtualize : $@convention(thin) (@in Int) -> () {
 bb0(%0 : $*Int):
   %1 = metatype $@thick Int.Type
-  %2 = witness_method $Int, #Comparable."<" : <Self where Self : Comparable> (Self.Type) -> (Self, Self) -> Bool : $@convention(witness_method: Comparable) <τ_0_0 where τ_0_0 : Comparable> (@in_guaranteed τ_0_0, @in_guaranteed τ_0_0, @thick τ_0_0.Type) -> Bool
+  %2 = witness_method $Int, #Comparable."<" : <Self where Self : Comparable, Self : ~Copyable> (Self.Type) -> (borrowing Self, borrowing Self) -> Bool : $@convention(witness_method: Comparable) <τ_0_0 where τ_0_0 : Comparable> (@in_guaranteed τ_0_0, @in_guaranteed τ_0_0, @thick τ_0_0.Type) -> Bool
   %3 = apply %2<Int>(%0, %0, %1) : $@convention(witness_method: Comparable) <τ_0_0 where τ_0_0 : Comparable> (@in_guaranteed τ_0_0, @in_guaranteed τ_0_0, @thick τ_0_0.Type) -> Bool
   %4 = tuple()
   return %4 : $()
@@ -124,7 +124,7 @@ bb0(%0 : $*Int, %1 : $*Int, %2 : $@thick Int.Type):
 
 sil_witness_table public_external [serialized] Int: Comparable module Swift {
   base_protocol Equatable: Int: Equatable module Swift
-  method #Comparable."<": <Self where Self : Comparable> (Self.Type) -> (Self, Self) -> Bool : @$sSiSLsSL1loiySbx_xtFZTW
+  method #Comparable."<": <Self where Self : Comparable, Self : ~Copyable> (Self.Type) -> (borrowing Self, borrowing Self) -> Bool : @$sSiSLsSL1loiySbx_xtFZTW
 }
 
 sil [ossa] @get_int_value : $@convention(thin) () -> Int32 {

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

@@ -71,8 +71,8 @@ Protocol CodingKey has added inherited protocol Copyable
 Protocol CodingKey has added inherited protocol Escapable
 Protocol Collection has added inherited protocol Copyable
 Protocol Collection has added inherited protocol Escapable
-Protocol Comparable has added inherited protocol Copyable
 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
@@ -246,6 +246,18 @@ Func Equatable.!=(_:_:) has parameter 1 changing from Default to Shared
 Func Equatable.==(_:_:) has generic signature change from <Self where Self : Swift.Equatable> to <Self where Self : Swift.Equatable, Self : ~Copyable>
 Func Equatable.==(_:_:) has parameter 0 changing from Default to Shared
 Func Equatable.==(_:_:) has parameter 1 changing from Default to Shared
+Func Comparable.<(_:_:) has generic signature change from <Self where Self : Swift.Comparable> to <Self where Self : Swift.Comparable, Self : ~Copyable>
+Func Comparable.<(_:_:) has parameter 0 changing from Default to Shared
+Func Comparable.<(_:_:) has parameter 1 changing from Default to Shared
+Func Comparable.<=(_:_:) has generic signature change from <Self where Self : Swift.Comparable> to <Self where Self : Swift.Comparable, Self : ~Copyable>
+Func Comparable.<=(_:_:) has parameter 0 changing from Default to Shared
+Func Comparable.<=(_:_:) has parameter 1 changing from Default to Shared
+Func Comparable.>(_:_:) has generic signature change from <Self where Self : Swift.Comparable> to <Self where Self : Swift.Comparable, Self : ~Copyable>
+Func Comparable.>(_:_:) has parameter 0 changing from Default to Shared
+Func Comparable.>(_:_:) has parameter 1 changing from Default to Shared
+Func Comparable.>=(_:_:) has generic signature change from <Self where Self : Swift.Comparable> to <Self where Self : Swift.Comparable, Self : ~Copyable>
+Func Comparable.>=(_:_:) has parameter 0 changing from Default to Shared
+Func Comparable.>=(_:_:) has parameter 1 changing from Default to Shared
 Func ManagedBuffer.create(minimumCapacity:makingHeaderWith:) has generic signature change from <Header, Element> to <Header, Element where Element : ~Copyable>
 Func ManagedBufferPointer.isUniqueReference() has generic signature change from <Header, Element> to <Header, Element where Element : ~Copyable>
 Func MemoryLayout.alignment(ofValue:) has generic signature change from <T> to <T where T : ~Copyable, T : ~Escapable>

test/api-digester/stability-stdlib-abi-without-asserts.test

@@ -189,8 +189,8 @@ Protocol CodingKey has added inherited protocol Copyable
 Protocol CodingKey has added inherited protocol Escapable
 Protocol Collection has added inherited protocol Copyable
 Protocol Collection has added inherited protocol Escapable
-Protocol Comparable has added inherited protocol Copyable
 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
@@ -546,6 +546,24 @@ Func Equatable.!=(_:_:) is now with @_preInverseGenerics
 Func Equatable.==(_:_:) has generic signature change from <Self where Self : Swift.Equatable> to <Self where Self : Swift.Equatable, Self : ~Copyable>
 Func Equatable.==(_:_:) has parameter 0 changing from Default to Shared
 Func Equatable.==(_:_:) has parameter 1 changing from Default to Shared
+Func Comparable.<(_:_:) has generic signature change from <Self where Self : Swift.Comparable> to <Self where Self : Swift.Comparable, Self : ~Copyable>
+Func Comparable.<(_:_:) has parameter 0 changing from Default to Shared
+Func Comparable.<(_:_:) has parameter 1 changing from Default to Shared
+Func Comparable.<=(_:_:) has generic signature change from <Self where Self : Swift.Comparable> to <Self where Self : Swift.Comparable, Self : ~Copyable>
+Func Comparable.<=(_:_:) has mangled name changing from 'static (extension in Swift):Swift.Comparable.<= infix(A, A) -> Swift.Bool' to 'static (extension in Swift):Swift.Comparable< where A: ~Swift.Copyable>.<= infix(A, A) -> Swift.Bool'
+Func Comparable.<=(_:_:) has parameter 0 changing from Default to Shared
+Func Comparable.<=(_:_:) has parameter 1 changing from Default to Shared
+Func Comparable.<=(_:_:) is now with @_preInverseGenerics
+Func Comparable.>(_:_:) has generic signature change from <Self where Self : Swift.Comparable> to <Self where Self : Swift.Comparable, Self : ~Copyable>
+Func Comparable.>(_:_:) has mangled name changing from 'static (extension in Swift):Swift.Comparable.> infix(A, A) -> Swift.Bool' to 'static (extension in Swift):Swift.Comparable< where A: ~Swift.Copyable>.> infix(A, A) -> Swift.Bool'
+Func Comparable.>(_:_:) has parameter 0 changing from Default to Shared
+Func Comparable.>(_:_:) has parameter 1 changing from Default to Shared
+Func Comparable.>(_:_:) is now with @_preInverseGenerics
+Func Comparable.>=(_:_:) has generic signature change from <Self where Self : Swift.Comparable> to <Self where Self : Swift.Comparable, Self : ~Copyable>
+Func Comparable.>=(_:_:) has mangled name changing from 'static (extension in Swift):Swift.Comparable.>= infix(A, A) -> Swift.Bool' to 'static (extension in Swift):Swift.Comparable< where A: ~Swift.Copyable>.>= infix(A, A) -> Swift.Bool'
+Func Comparable.>=(_:_:) has parameter 0 changing from Default to Shared
+Func Comparable.>=(_:_:) has parameter 1 changing from Default to Shared
+Func Comparable.>=(_:_:) is now with @_preInverseGenerics
 Func ManagedBuffer.create(minimumCapacity:makingHeaderWith:) has generic signature change from <Header, Element> to <Header, Element where Element : ~Copyable>
 Func ManagedBuffer.create(minimumCapacity:makingHeaderWith:) has mangled name changing from 'static Swift.ManagedBuffer.create(minimumCapacity: Swift.Int, makingHeaderWith: (Swift.ManagedBuffer<A, B>) throws -> A) throws -> Swift.ManagedBuffer<A, B>' to 'static (extension in Swift):Swift.ManagedBuffer< where B: ~Swift.Copyable>.create(minimumCapacity: Swift.Int, makingHeaderWith: (Swift.ManagedBuffer<A, B>) throws -> A) throws -> Swift.ManagedBuffer<A, B>'
 Func ManagedBuffer.create(minimumCapacity:makingHeaderWith:) is now with @_preInverseGenerics

test/stdlib/NoncopyableEquatable.swift

@@ -32,7 +32,13 @@ func isNotSame<T: Equatable & ~Copyable>(_ lhs: borrowing T, _ rhs: borrowing T)
     lhs != rhs
 }
 
-NoncopyableEquatableTests.test("comparing noncopyables") {
+extension Noncopyable: Comparable {
+    static func <(lhs: borrowing Self, rhs: borrowing Self) -> Bool {
+        lhs.i < rhs.i
+    }
+}
+
+NoncopyableEquatableTests.test("equating noncopyables") {
     let a = Noncopyable(i: 1)
     let b = Noncopyable(i: 2)
     let c = Noncopyable(i: 1)
@@ -43,4 +49,26 @@ NoncopyableEquatableTests.test("comparing noncopyables") {
     expectTrue(isNotSame(a,b))
 }
 
+@available(SwiftStdlib 6.2, *)
+extension InlineArray where Element: Comparable & ~Copyable {
+    func minIndex() -> Int? {
+        indices.min { self[$0] < self[$1] }
+    }
+}
+
+NoncopyableEquatableTests.test("comparing noncopyables") {
+
+    guard #available(SwiftStdlib 6.2, *) else { return }
+
+    let a = Noncopyable(i: 1)
+    let b = Noncopyable(i: 2)
+    let c = Noncopyable(i: 0)
+
+    expectTrue(a > c)
+    expectFalse(a <= c)
+
+    let array: [3 of Noncopyable] = [a,b,c]
+    expectTrue(array.minIndex() == 2)
+ }
+
 runAllTests()

test/stdlib/StringDiagnostics.swift

@@ -34,14 +34,18 @@ func testAmbiguousStringComparisons(s: String) {
   let nsString = s as NSString
   let a1 = s as NSString == nsString
   let a2 = s as NSString != nsString
-  let a3 = s < nsString // expected-error{{'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?}} {{24-24= as String}}
+  let a3 = s < nsString 
+  // expected-error@-1{{binary operator '<' cannot be applied to operands of type 'String' and 'NSString'}}
+  // expected-note@-2{{overloads for '<' exist with these partially matching parameter lists: (String, String)}}
   let a4 = s <= nsString // expected-error{{'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?}} {{25-25= as String}}
   let a5 = s >= nsString // expected-error{{'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?}} {{25-25= as String}}
   let a6 = s > nsString // expected-error{{'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?}} {{24-24= as String}}
   // now the other way
   let a7 = nsString == s as NSString
   let a8 = nsString != s as NSString
-  let a9 = nsString < s // expected-error{{'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?}} {{20-20= as String}}
+  let a9 = nsString < s 
+  // expected-error@-1{{binary operator '<' cannot be applied to operands of type 'NSString' and 'String'}}
+  // expected-note@-2{{overloads for '<' exist with these partially matching parameter lists: (String, String)}}
   let a10 = nsString <= s // expected-error{{'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?}} {{21-21= as String}}
   let a11 = nsString >= s // expected-error{{'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?}} {{21-21= as String}}
   let a12 = nsString > s // expected-error{{'NSString' is not implicitly convertible to 'String'; did you mean to use 'as' to explicitly convert?}} {{21-21= as String}}