Fix clang-tidy performance-unnecessary-copy-initialization warnings

Detected by clang-tidy-19

src/core/model/des-metrics.cc

@@ -41,7 +41,7 @@ DesMetrics::Initialize(std::vector<std::string> args, std::string outDir /* = ""
     std::string model_name("desTraceFile");
     if (!args.empty())
     {
-        std::string arg0 = args[0];
+        const std::string& arg0 = args[0];
         model_name = SystemPath::Split(arg0).back();
     }
     std::string jsonFile = model_name + ".json";

src/core/model/system-path.cc

@@ -351,7 +351,7 @@ Exists(const std::string path)
 
     // Check if the file itself exists
     auto tokens = Split(path);
-    std::string file = tokens.back();
+    const std::string& file = tokens.back();
 
     if (file.empty())
     {

src/internet/model/ipv4-interface.cc

@@ -357,7 +357,7 @@ Ipv4Interface::RemoveAddress(uint32_t index)
     {
         if (tmp == index)
         {
-            Ipv4InterfaceAddress addr = *i;
+            const Ipv4InterfaceAddress& addr = *i;
             m_ifaddrs.erase(i);
             if (!m_removeAddressCallback.IsNull())
             {
@@ -388,7 +388,7 @@ Ipv4Interface::RemoveAddress(Ipv4Address address)
     {
         if ((*it).GetLocal() == address)
         {
-            Ipv4InterfaceAddress ifAddr = *it;
+            const Ipv4InterfaceAddress& ifAddr = *it;
             m_ifaddrs.erase(it);
             if (!m_removeAddressCallback.IsNull())
             {

src/netanim/model/animation-interface.cc

@@ -2520,7 +2520,7 @@ AnimationInterface::WriteXmlRp(uint32_t nodeId,
     element.AddAttribute("c", rpElements.size());
     for (auto i = rpElements.begin(); i != rpElements.end(); ++i)
     {
-        Ipv4RoutePathElement rpElement = *i;
+        const Ipv4RoutePathElement& rpElement = *i;
         AnimXmlElement rpeElement("rpe");
         rpeElement.AddAttribute("n", rpElement.nodeId);
         rpeElement.AddAttribute("nH", rpElement.nextHop.c_str());

src/network/test/packet-test-suite.cc

@@ -642,7 +642,7 @@ PacketTest::DoRun()
 
     {
         Packet c0 = *copy;
-        Packet c1 = *copy;
+        Packet c1 = *copy; // NOLINT(performance-unnecessary-copy-initialization)
         c0 = c1;
         CHECK(&c0, 1, E(1, 0, 1000));
         CHECK(&c1, 1, E(1, 0, 1000));

src/stats/model/omnet-data-output.cc

@@ -104,7 +104,7 @@ OmnetDataOutput::Output(DataCollector& dc)
 
     for (auto i = dc.MetadataBegin(); i != dc.MetadataEnd(); i++)
     {
-        std::pair<std::string, std::string> blob = (*i);
+        const auto& blob = (*i);
         scalarFile << "attr \"" << blob.first << "\" \"" << blob.second << "\"" << std::endl;
     }
 
@@ -115,7 +115,7 @@ OmnetDataOutput::Output(DataCollector& dc)
     }
     for (auto i = dc.MetadataBegin(); i != dc.MetadataEnd(); i++)
     {
-        std::pair<std::string, std::string> blob = (*i);
+        const auto& blob = (*i);
         if (isNumeric(blob.second))
         {
             scalarFile << "scalar . \"" << blob.first << "\" \"" << blob.second << "\""

src/stats/model/sqlite-data-output.cc

@@ -107,7 +107,7 @@ SqliteDataOutput::Output(DataCollector& dc)
 
     for (auto i = dc.MetadataBegin(); i != dc.MetadataEnd(); i++)
     {
-        std::pair<std::string, std::string> blob = (*i);
+        const auto& blob = (*i);
         SQLiteOutput::SpinReset(stmt);
         m_sqliteOut->Bind(stmt, 1, run);
         m_sqliteOut->Bind(stmt, 2, blob.first);

src/wifi/helper/wifi-phy-rx-trace-helper.cc

@@ -957,7 +957,7 @@ WifiPhyRxTraceSink::CountStatistics(uint32_t nodeId, uint32_t deviceId, uint8_t
         auto mapOfDevices = m_completedRecords.at(nodeId);
         if (mapOfDevices.contains(deviceId))
         {
-            auto mapOfLinks = mapOfDevices.at(deviceId);
+            const auto& mapOfLinks = mapOfDevices.at(deviceId);
             if (mapOfLinks.contains(linkId))
             {
                 auto vectorOfRecords = mapOfLinks.at(linkId);

src/wimax/model/bs-net-device.cc

@@ -1180,7 +1180,7 @@ BaseStationNetDevice::MarkUplinkAllocations()
     std::list<OfdmUlMapIe> uplinkAllocations = m_uplinkScheduler->GetUplinkAllocations();
     for (auto iter = uplinkAllocations.begin(); iter != uplinkAllocations.end(); ++iter)
     {
-        OfdmUlMapIe uplinkAllocation = *iter;
+        const OfdmUlMapIe& uplinkAllocation = *iter;
 
         if (uplinkAllocation.GetUiuc() == OfdmUlBurstProfile::UIUC_END_OF_MAP)
         {

src/wimax/model/ss-net-device.cc

@@ -1166,7 +1166,7 @@ SubscriberStationNetDevice::ProcessUlMap(const UlMap& ulmap)
 
     for (auto iter = ulMapElements.begin(); iter != ulMapElements.end(); ++iter)
     {
-        OfdmUlMapIe ulMapIe = *iter;
+        const OfdmUlMapIe& ulMapIe = *iter;
 
         if (ulMapIe.GetUiuc() == OfdmUlBurstProfile::UIUC_END_OF_MAP)
         {
@@ -1267,7 +1267,7 @@ SubscriberStationNetDevice::ProcessDcd(const Dcd& dcd)
 
     for (auto iter = dlBurstProfiles.begin(); iter != dlBurstProfiles.end(); ++iter)
     {
-        OfdmDlBurstProfile brstProfile = *iter;
+        const OfdmDlBurstProfile& brstProfile = *iter;
 
         /*NS-2 does this, may be not correct, assumes DIUC/UIUC to
          modulation type mapping in DCD/UCD may change over time*/
@@ -1302,7 +1302,7 @@ SubscriberStationNetDevice::ProcessUcd(const Ucd& ucd)
 
     for (auto iter = ulBurstProfiles.begin(); iter != ulBurstProfiles.end(); ++iter)
     {
-        OfdmUlBurstProfile brstProfile = *iter;
+        const OfdmUlBurstProfile& brstProfile = *iter;
 
         /*NS-2 does this, may be not correct, assumes DIUC/UIUC to
          modulation type mapping in DCD/UCD may change over time*/