what does 'deprecated' mean with respect to "bare structure types"?

[Luís Oliveira]

On Tue, Jun 11, 2013 at 2:15 PM, james anderson <james.anderson at setf.de> wrote:
> "arbitrarily depending on context" does not make sense. it is a contradiction in terms. there must be more to the argument than that.

Consider some (defstruct foo ...). The deprecated foreign type it
defines is FOO. In the context of structure definitions or
WITH-FOREIGN-OBJECT, it has value semantics. In the context of mem-ref
it behaves like a no-op. In the context of function calls, it behaves
like a pointer. That's the "depending on context" and "confusing" part
of the argument.

FOO sometimes behaves like a pointer is because there wasn't support
for passing-by-value (nor plans to support it) and sometimes behaves
as a no-op because aggregate type translation was likewise mostly
missing at the time. That's the "arbitrary" part: the semantics of FOO
were dictated by the historical evolution of CFFI rather than a
principled approach to the current feature set. They appear to be
random to someone unaware of that evolution.

Now contrast all that with the intuitive and consistent semantics of
(:POINTER (:STRUCT FOO)) and (:STRUCT FOO).

Cheers,

--
Luís Oliveira
http://r42.eu/~luis/