shared: add nm_cmp_int2ptr_p_with_data() helper

A cmp() implementation, for sorting an array with pointers, where each
pointer is an inteter according to GPOINTER_TO_INT().

That cames for example handy, if you have a GHashTable with keys
GINT_TO_POINTER(). Then you get the list of keys via
g_hash_table_get_keys_as_array() and want to sort them.

1 files changed, 19 insertions, 0 deletions

diff --git a/shared/nm-utils/nm-macros-internal.h b/shared/nm-utils/nm-macros-internal.h
index 4ee59f195e..852a87df5b 100644
--- a/shared/nm-utils/nm-macros-internal.h
+++ b/shared/nm-utils/nm-macros-internal.h
@@ -1049,6 +1049,25 @@ nm_cmp_uint32_p_with_data (gconstpointer p_a, gconstpointer p_b, gpointer user_d
 	return 0;
 }
 
+static inline int
+nm_cmp_int2ptr_p_with_data (gconstpointer p_a, gconstpointer p_b, gpointer user_data)
+{
+	/* p_a and p_b are two pointers to a pointer, where the pointer is
+	 * interpreted as a integer using GPOINTER_TO_INT().
+	 *
+	 * That is the case of a hash-table that uses GINT_TO_POINTER() to
+	 * convert integers as pointers, and the resulting keys-as-array
+	 * array. */
+	const int a = GPOINTER_TO_INT (*((gconstpointer *) p_a));
+	const int b = GPOINTER_TO_INT (*((gconstpointer *) p_b));
+
+	if (a < b)
+		return -1;
+	if (a > b)
+		return 1;
+	return 0;
+}
+
 /*****************************************************************************/
 
 /* Taken from systemd's UNIQ_T and UNIQ macros. */