diff -r ec50abb285ad -r dfd0403ff8b6 test/test_utils.cpp
--- a/test/test_utils.cpp	Thu Feb 02 20:25:34 2023 +0100
+++ b/test/test_utils.cpp	Wed Feb 08 18:56:58 2023 +0100
@@ -39,6 +39,16 @@
     }
 }
 
+TEST(Utils, swap_ptr) {
+    int i = 5;
+    int j = 8;
+    int *ip = &i;
+    int *jp = &j;
+    cx_swap_ptr(ip, jp);
+    EXPECT_EQ(ip, &j);
+    EXPECT_EQ(jp, &i);
+}
+
 TEST(Utils, szmul) {
     size_t r;
     int e;