Implicitly typed lambdas with [UnscopedRef] don't match their own anonymous delegate types #63565
Description
Version Used:
commit e041ae9802b68f7c6f6903ec92b56d27ff0caec3
Author: Youssef Victor <youssefvictor00@gmail.com>
Date: Wed Aug 24 16:00:43 2022 +0200
Delete extra character in Syntax.xml (#63561)
Steps to Reproduce:
using System.Diagnostics.CodeAnalysis;
public ref struct RefStruct { }
public struct RegularStruct { }
delegate void D1([UnscopedRef] ref RefStruct s);
delegate void D2([UnscopedRef] out RegularStruct s);
public class C
{
public void M()
{
var x = ([UnscopedRef] ref RefStruct s) => { }; // error CS8986: The 'scoped' modifier of parameter 's' doesn't match target '<anonymous delegate>'.
var y = ([UnscopedRef] out RegularStruct s) => { }; // error CS8986: The 'scoped' modifier of parameter 's' doesn't match target '<anonymous delegate>'.
D1 q = ([UnscopedRef] ref RefStruct s) => { };
D2 w = ([UnscopedRef] out RegularStruct s) => { };
}
}
namespace System.Diagnostics.CodeAnalysis
{
[AttributeUsage(AttributeTargets.All, Inherited = false)]
internal sealed class UnscopedRefAttribute : Attribute
{
public UnscopedRefAttribute()
{
}
}
}Expected Behavior:
No errors for lambda expressions assigned to var variables. The anonymous delegates created for them should have [UnscopedRef] annotations on their parameters
Actual Behavior:
Lambda expressions with completely valid signatures (as demonstrated by D1, D2 and corresponding lambda expressions) produce errors due to mismatches with their own implicit types