Version Used: #error version reports Compiler version: '4.5.0-2.22527.10 (401447a2)'. Language version: 10.0.

Steps to Reproduce:

1. See discussion: Why can't we declare a top-level delegate returning a value-tuple?

   In the following Program.cs listing, only the second to last delegate, I() gives off compile errors.

   System.Console.WriteLine("Hello");
   
   delegate int F(int x);
   delegate int G((int, int) x);
   delegate System.ValueTuple<int, int> H(int x);
   delegate (int, int) I(int x);
   class _ {
      delegate (int, int) J(int x);
   }

   As if to compensate for its uniqueness, it gives off tons of errors, actually:

    1: error CS8803: Top-level statements must precede namespace and type declarations.
   14: error CS1001: Identifier expected
   19: error CS1001: Identifier expected
   21: error CS1514: { expected
   21: error CS1002: ; expected
   23: error CS1525: Invalid expression term 'int'
   27: error CS1003: Syntax error, ',' expected
   

   ... But not one that would help me understand how I angered the compiler.

   Just wondering. 😗

2. The above using sharplab.

Diagnostic Id: No IDE... diagnostic to show.
Expected Behavior: We can declare value-tuple-returning delegates at top-level.
Actual Behavior: We can't.