C domain: allow inline reference to pointer of a defined type

[marxin]

It's quite common that one needs to explain that a pointer of a type is returned:

.. c:type:: my_type

This works :c:type:`my_type`, but I would like to point
to a pointer of the type (:c:type:`my_type *`).

but one gets:

/tmp/demo/source/index.rst:15: WARNING: Unparseable C cross-reference: 'my_type *'
Invalid C declaration: Expected end of definition. [error at 8]
  my_type *
  --------^

@jakobandersen Is it something that can be supported, please?

[jakobandersen]

The type directive is for declaring a type alias so that won't work.
If it's a return type then something like the following can be done:

... c:function:: Foo *f()

   :returns: a pointer to the thing.
   :rtype: Foo*

In general you can use the expr role in inline text, it accepts both expressions and types.

[marxin]

Yep, thanks, :expr: role works very well!