add missing header include

bsyrowik · bsyrowik · commit fe3d0a44c9a4 · 2022-06-02T11:54:11.000-07:00
diff --git a/src/acl_usm.cpp b/src/acl_usm.cpp
@@ -6,6 +6,7 @@
 #include <cassert>
 #include <cstdio>
 #include <iostream>
+#include <optional>
 #include <sstream>
 #include <string>
 #include <unordered_set>
