----------
define c-struct <objc-object>
  slot is-a :: <objc-class*>;
  pointer-type-name: <objc-object*>;
  c-name: "objc_object";
end;
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This fails with the following error.

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Serious warning at objective-c-runtime:18:

Unexpected token "::".

objective-c-runtime:17:             --
objective-c-runtime:18:   slot is-a :: <objc-class*>;
objective-c-runtime:19:             --
----------