[gjs/arg-inlines: 7/9] gi: Use specialized GIArgument wrapper to handle enum types

[Philip Chimento <pchimento src gnome org>]

commit e9afe6de675f2839a8e58b82779f0d530325b582
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Mon May 18 16:11:23 2020 +0200

    gi: Use specialized GIArgument wrapper to handle enum types
    
    Enums and flags must be saved as int internally, so define a specialized
    wrapper for this so that we can automatically and safely ensure everywhere that
    we're respecting this

 gi/arg-inl.h | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/gi/arg-inl.h b/gi/arg-inl.h
index f1def9d5..d8229c08 100644
--- a/gi/arg-inl.h
+++ b/gi/arg-inl.h
@@ -140,6 +140,12 @@ GJS_USE inline decltype(auto) gjs_arg_member<std::nullptr_t>(GIArgument* arg) {
     return gjs_arg_member(arg, &GIArgument::v_pointer);
 }
 
+template <>
+GJS_USE inline decltype(auto) gjs_arg_member<int, GI_TYPE_TAG_INTERFACE>(
+    GIArgument* arg) {
+    return gjs_arg_member(arg, &GIArgument::v_int);
+}
+
 template <typename T, GITypeTag TAG = GI_TYPE_TAG_VOID>
 inline void gjs_arg_set(GIArgument* arg, T v) {
     gjs_arg_member<T, TAG>(arg) = v;