Fix build with -D_GLIBCXX_DEBUG [-Werror=range-loop-construct].

diff --git a/src/mc/explo/udpor/EventSet_test.cpp b/src/mc/explo/udpor/EventSet_test.cpp
index bfd1379..684ac5d 100644 (file)
--- a/src/mc/explo/udpor/EventSet_test.cpp
+++ b/src/mc/explo/udpor/EventSet_test.cpp
@@ -1080,7 +1080,7 @@ TEST_CASE("simgrid::mc::udpor::EventSet: Topological Ordering Property Observed
 
     const EventSet subset = [&subset_of_iterators]() {
       EventSet subset_local;
-      for (const auto iter : subset_of_iterators) {
+      for (const auto& iter : subset_of_iterators) {
         subset_local.insert(*iter);
       }
       return subset_local;