diff -r c067394737ca -r 96fa7fa6af4f src/string.c
--- a/src/string.c	Sat Sep 03 14:56:07 2022 +0200
+++ b/src/string.c	Sat Sep 03 15:11:23 2022 +0200
@@ -430,3 +430,15 @@
                        suffix.ptr, suffix.length) == 0;
 #endif
 }
+
+void cx_strlower(cxmutstr string) {
+    cx_for_n(i, string.length) {
+        string.ptr[i] = tolower(string.ptr[i]);
+    }
+}
+
+void cx_strupper(cxmutstr string) {
+    cx_for_n(i, string.length) {
+        string.ptr[i] = toupper(string.ptr[i]);
+    }
+}