 func protocolCompositionNotSupported(_: SomeProto & Sequence<Int>) {}
 // expected-error@-1 {{non-protocol, non-class type 'Sequence<Int>' cannot be used within a protocol-constrained type}}
 
+/// More regression tests
+
 protocol DoubleWide<X, Y> {
   var x: X { get }
   var y: Y { get }

// RUN: %target-typecheck-verify-swift -requirement-machine-protocol-signatures=verify -requirement-machine-inferred-signatures=verify -enable-parameterized-protocol-types -disable-availability-checking

// RUN: not %target-swift-frontend -typecheck %s -debug-generic-signatures -requirement-machine-protocol-signatures=verify -enable-parameterized-protocol-types -requirement-machine-inferred-signatures=verify -disable-availability-checking 2>&1 | %FileCheck %s


/// Test some invalid syntax first

  associatedtype E
}

// https://bugs.swift.org/browse/SR-15979 - the GenericSignatureBuilder doesn't like this protocol.

// CHECK-LABEL: .Recursive@
// CHECK-NEXT: Requirement signature: <Self where Self.[Recursive]B == Self.[Recursive]D.[Recursive]B, Self.[Recursive]C == Self.[Recursive]D.[Recursive]C, Self.[Recursive]D : Recursive>
protocol Recursive<B, C> {
  associatedtype D: Recursive<B, C> = Self
}

/// Parametrized protocol in where clause of concrete type

