Re: Transfer rules of inout parameters

[Christoph Reiter <reiter christoph gmail com>]

On Fri, Feb 9, 2018 at 12:31 PM, Philip Withnall <philip tecnocode co uk> wrote:
>  • Instead, allow separate annotations for the ‘in’ and ‘out’ modes for
> a parameter; something like (in (nullable) (transfer none)) (out (not
> nullable) (transfer full)).
>  • That’s because quite a few of the annotations could theoretically
> differ between the modes: nullability, transfer and array length.
>  • Because this is tricky to reason about, don’t have a default:
> require that everything is always specified for inout parameters.
>  • My suggested syntax is horrible.

Somewhat related, having two separate descriptions for in/out would
also be nice for the binding documentation as the in and out parts get
split into a parameter and a return value, each needing their own
description. For example with gtk_init_check [0] this currently
results in a confusing duplicated description which focuses on the C
value type instead of the actual values being transferred [1].

[0] https://gitlab.gnome.org/GNOME/gtk/blob/3.22.26/gtk/gtkmain.c#L1073
[1] https://lazka.github.io/pgi-docs/#Gtk-3.0/functions.html#Gtk.init_check