Struct interfaces not supported on Cocoa platform?

Elements C#
1

Following code will trigger (E417) Interface types not allowed on unmanaged records error.

public interface ITestInterface {}
public struct AStruct : ITestInterface
{
	int testfield;
}

It’s strange since struct interfaces should be part of c# spec:

18.1.2 Struct interfaces

A struct declaration can include a struct-interfaces specification, in which case the struct is said to implement the given interface types.
struct-interfaces:
: interface-type-list
The handling of interfaces on multiple parts of a partial struct declaration (§17.1.4) are discussed further in §17.1.2.2.
Interface implementations are discussed further in §20.4.

2

on the Cocoa platform, structs are regular C-level structs, not objects. Thats required, because otherwise you could not interact with the many Cocoa and CoreFoundation APIs that take structs (such as say, CGPoints).

3

Thanks marc.

Is there any document we can refer to for that kind of platform depended language behavior?

4

http://www.elementswiki.com/en/Language_Platform_Differences should have this info. the text refers to Oxygene mostly, but (language syntaxes aside) should equally apply to RemObjects C#. I’ll gte that mage reviewed and brought up to speed to cleanly cover both languages,