wifi: Fix operator< for HeRu

src/wifi/model/he/he-ru.cc

@@ -23,6 +23,7 @@
 #include "ns3/assert.h"
 
 #include <optional>
+#include <tuple>
 
 namespace ns3
 {
@@ -896,8 +897,8 @@ HeRu::RuSpec::operator<(const RuSpec& other) const
     // we do not compare the RU PHY indices because they may be uninitialized for
     // one of the compared RUs. This event should not cause the comparison to evaluate
     // to false
-    return m_ruType < other.m_ruType || m_index < other.m_index ||
-           m_primary80MHz < other.m_primary80MHz;
+    return std::tie(m_ruType, m_index, m_primary80MHz) <
+           std::tie(other.m_ruType, other.m_index, other.m_primary80MHz);
 }
 
 } // namespace ns3