[gjs/arg-inlines: 5/9] arg: Add utility function to unset a GIArgument depending on type

[Philip Chimento <pchimento src gnome org>]

commit 41db0aaeb4fa61610823d6638168e58629f6befa
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Mon May 11 02:21:40 2020 +0200

    arg: Add utility function to unset a GIArgument depending on type

 gi/arg-inl.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)
---
diff --git a/gi/arg-inl.h b/gi/arg-inl.h
index 33366aa5..e199cee7 100644
--- a/gi/arg-inl.h
+++ b/gi/arg-inl.h
@@ -169,3 +169,15 @@ GJS_USE inline gboolean gjs_g_argument_value_get<gboolean, GI_TYPE_TAG_BOOLEAN>(
     GIArgument* arg) {
     return !!gjs_g_argument_value<bool>(arg);
 }
+
+template <typename T, GITypeTag TAG = GI_TYPE_TAG_VOID>
+inline std::enable_if_t<!std::is_pointer<T>::value> gjs_g_argument_value_unset(
+    GIArgument* arg) {
+    gjs_g_argument_value_set<T, TAG>(arg, static_cast<T>(0));
+}
+
+template <typename T, GITypeTag TAG = GI_TYPE_TAG_VOID>
+inline std::enable_if_t<std::is_pointer<T>::value> gjs_g_argument_value_unset(
+    GIArgument* arg) {
+    gjs_g_argument_value_set<T, TAG>(arg, nullptr);
+}