Use range-based for loops (C++11) when looping over map elements

Before this commit:

  for (std::map<T1, T2>::iterator x = y.begin(); x != y.end(); ++x) {
  }

After this commit:

  for (auto& x : y) {
  }

src/addrdb.h

@@ -55,7 +55,7 @@ class CBanEntry
         banReason = BanReasonUnknown;
     }
 
-    std::string banReasonToString()
+    std::string banReasonToString() const
     {
         switch (banReason) {
         case BanReasonNodeMisbehaving:

src/addrman.cpp

@@ -405,9 +405,9 @@ int CAddrMan::Check_()
     if (vRandom.size() != nTried + nNew)
         return -7;
 
-    for (std::map<int, CAddrInfo>::iterator it = mapInfo.begin(); it != mapInfo.end(); it++) {
-        int n = (*it).first;
-        CAddrInfo& info = (*it).second;
+    for (const auto& entry : mapInfo) {
+        int n = entry.first;
+        const CAddrInfo& info = entry.second;
         if (info.fInTried) {
             if (!info.nLastSuccess)
                 return -1;

src/addrman.h

@@ -325,18 +325,18 @@ class CAddrMan
         s << nUBuckets;
         std::map<int, int> mapUnkIds;
         int nIds = 0;
-        for (std::map<int, CAddrInfo>::const_iterator it = mapInfo.begin(); it != mapInfo.end(); it++) {
-            mapUnkIds[(*it).first] = nIds;
-            const CAddrInfo& info = (*it).second;
+        for (const auto& entry : mapInfo) {
+            mapUnkIds[entry.first] = nIds;
+            const CAddrInfo &info = entry.second;
             if (info.nRefCount) {
                 assert(nIds != nNew); // this means nNew was wrong, oh ow
                 s << info;
                 nIds++;
             }
         }
         nIds = 0;
-        for (std::map<int, CAddrInfo>::const_iterator it = mapInfo.begin(); it != mapInfo.end(); it++) {
-            const CAddrInfo& info = (*it).second;
+        for (const auto& entry : mapInfo) {
+            const CAddrInfo &info = entry.second;
             if (info.fInTried) {
                 assert(nIds != nTried); // this means nTried was wrong, oh ow
                 s << info;

src/net.cpp

@@ -97,11 +97,11 @@ bool GetLocal(CService& addr, const CNetAddr* paddrPeer)
     int nBestReachability = -1;
     {
         LOCK(cs_mapLocalHost);
-        for (std::map<CNetAddr, LocalServiceInfo>::iterator it = mapLocalHost.begin(); it != mapLocalHost.end(); it++) {
-            int nScore = (*it).second.nScore;
-            int nReachability = (*it).first.GetReachabilityFrom(paddrPeer);
+        for (const auto& entry : mapLocalHost) {
+            int nScore = entry.second.nScore;
+            int nReachability = entry.first.GetReachabilityFrom(paddrPeer);
             if (nReachability > nBestReachability || (nReachability == nBestReachability && nScore > nBestScore)) {
-                addr = CService((*it).first, (*it).second.nPort);
+                addr = CService(entry.first, entry.second.nPort);
                 nBestReachability = nReachability;
                 nBestScore = nScore;
             }

src/qt/bantablemodel.cpp

@@ -56,11 +56,11 @@ class BanTablePriv
 
         cachedBanlist.clear();
         cachedBanlist.reserve(banMap.size());
-        for (banmap_t::iterator it = banMap.begin(); it != banMap.end(); it++)
+        for (const auto& entry : banMap)
         {
             CCombinedBan banEntry;
-            banEntry.subnet = (*it).first;
-            banEntry.banEntry = (*it).second;
+            banEntry.subnet = entry.first;
+            banEntry.banEntry = entry.second;
             cachedBanlist.append(banEntry);
         }
 

src/rpc/net.cpp

@@ -521,11 +521,11 @@ UniValue listbanned(const JSONRPCRequest& request)
     g_connman->GetBanned(banMap);
 
     UniValue bannedAddresses(UniValue::VARR);
-    for (banmap_t::iterator it = banMap.begin(); it != banMap.end(); it++)
+    for (const auto& entry : banMap)
     {
-        CBanEntry banEntry = (*it).second;
+        const CBanEntry& banEntry = entry.second;
         UniValue rec(UniValue::VOBJ);
-        rec.pushKV("address", (*it).first.ToString());
+        rec.pushKV("address", entry.first.ToString());
         rec.pushKV("banned_until", banEntry.nBanUntil);
         rec.pushKV("ban_created", banEntry.nCreateTime);
         rec.pushKV("ban_reason", banEntry.banReasonToString());

src/serialize.h

@@ -1009,8 +1009,8 @@ template <typename Stream, typename K, typename T, typename Pred, typename A>
 void Serialize(Stream& os, const std::map<K, T, Pred, A>& m)
 {
     WriteCompactSize(os, m.size());
-    for (typename std::map<K, T, Pred, A>::const_iterator mi = m.begin(); mi != m.end(); ++mi)
-        Serialize(os, (*mi));
+    for (const auto& entry : m)
+        Serialize(os, entry);
 }
 
 template <typename Stream, typename K, typename T, typename Pred, typename A>

src/test/coins_tests.cpp

@@ -200,8 +200,8 @@ class CCoinsViewCacheTest : public CCoinsViewCache
                      memusage::DynamicUsage(cacheSaplingAnchors) +
                      memusage::DynamicUsage(cacheSaplingNullifiers);
         size_t count = 0;
-        for (CCoinsMap::iterator it = cacheCoins.begin(); it != cacheCoins.end(); it++) {
-            ret += memusage::DynamicUsage(it->second.coin);
+        for (const auto& entry : cacheCoins) {
+            ret += memusage::DynamicUsage(entry.second.coin);
             ++count;
         }
         BOOST_CHECK_EQUAL(GetCacheSize(), count);
@@ -690,15 +690,15 @@ BOOST_AUTO_TEST_CASE(coins_cache_simulation_test)
 
         // Once every 1000 iterations and at the end, verify the full cache.
         if (InsecureRandRange(1000) == 1 || i == NUM_SIMULATION_ITERATIONS - 1) {
-            for (auto it = result.begin(); it != result.end(); it++) {
-                bool have = stack.back()->HaveCoin(it->first);
-                const Coin& coin = stack.back()->AccessCoin(it->first);
+            for (const auto& entry : result) {
+                bool have = stack.back()->HaveCoin(entry.first);
+                const Coin& coin = stack.back()->AccessCoin(entry.first);
                 BOOST_CHECK(have == !coin.IsSpent());
-                BOOST_CHECK(coin == it->second);
+                BOOST_CHECK(coin == entry.second);
                 if (coin.IsSpent()) {
                     missed_an_entry = true;
                 } else {
-                    BOOST_CHECK(stack.back()->HaveCoinInCache(it->first));
+                    BOOST_CHECK(stack.back()->HaveCoinInCache(entry.first));
                     found_an_entry = true;
                 }
             }
@@ -895,11 +895,11 @@ BOOST_AUTO_TEST_CASE(updatecoins_simulation_test)
 
         // Once every 1000 iterations and at the end, verify the full cache.
         if (InsecureRandRange(1000) == 1 || i == NUM_SIMULATION_ITERATIONS - 1) {
-            for (auto it = result.begin(); it != result.end(); it++) {
-                bool have = stack.back()->HaveCoin(it->first);
-                const Coin& coin = stack.back()->AccessCoin(it->first);
+            for (const auto& entry : result) {
+                bool have = stack.back()->HaveCoin(entry.first);
+                const Coin& coin = stack.back()->AccessCoin(entry.first);
                 BOOST_CHECK(have == !coin.IsSpent());
-                BOOST_CHECK(coin == it->second);
+                BOOST_CHECK(coin == entry.second);
             }
         }
 

src/validation.cpp

@@ -3948,8 +3948,8 @@ void static CheckBlockIndex()
 
     // Build forward-pointing map of the entire block tree.
     std::multimap<CBlockIndex*, CBlockIndex*> forward;
-    for (BlockMap::iterator it = mapBlockIndex.begin(); it != mapBlockIndex.end(); it++) {
-        forward.emplace(it->second->pprev, it->second);
+    for (auto& entry : mapBlockIndex) {
+        forward.emplace(entry.second->pprev, entry.second);
     }
 
     assert(forward.size() == mapBlockIndex.size());

src/wallet/wallet.cpp

@@ -2512,7 +2512,6 @@ CWallet::OutputAvailabilityResult CWallet::CheckOutputAvailability(
 
     // Check if we should include zero value utxo
     if (output.nValue <= 0) return res;
-
     if (fCoinsSelected && coinControl && !coinControl->fAllowOtherInputs && !coinControl->IsSelected(COutPoint(wtxid, outIndex)))
         return res;
 
@@ -3893,9 +3892,9 @@ void CWallet::GetKeyBirthTimes(std::map<CKeyID, int64_t>& mapKeyBirth) const
 
     // find first block that affects those keys, if there are any left
     std::vector<CKeyID> vAffected;
-    for (std::map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); it++) {
+    for (const auto& entry : mapWallet) {
         // iterate over all wallet transactions...
-        const CWalletTx& wtx = (*it).second;
+        const CWalletTx &wtx = entry.second;
         BlockMap::const_iterator blit = mapBlockIndex.find(wtx.m_confirm.hashBlock);
         if (blit != mapBlockIndex.end() && chainActive.Contains(blit->second)) {
             // ... which are already in a block
@@ -3915,8 +3914,8 @@ void CWallet::GetKeyBirthTimes(std::map<CKeyID, int64_t>& mapKeyBirth) const
     }
 
     // Extract block timestamps for those keys
-    for (std::map<CKeyID, CBlockIndex*>::const_iterator it = mapKeyFirstBlock.begin(); it != mapKeyFirstBlock.end(); it++)
-        mapKeyBirth[it->first] = it->second->GetBlockTime() - TIMESTAMP_WINDOW; // block times can be 2h off
+    for (const auto& entry : mapKeyFirstBlock)
+        mapKeyBirth[entry.first] = entry.second->GetBlockTime() - TIMESTAMP_WINDOW; // block times can be 2h off
 }
 
 bool CWallet::AddDestData(const CTxDestination& dest, const std::string& key, const std::string& value)

src/zmq/zmqnotificationinterface.cpp

@@ -39,15 +39,15 @@ CZMQNotificationInterface* CZMQNotificationInterface::Create()
     factories["pubrawblock"] = CZMQAbstractNotifier::Create<CZMQPublishRawBlockNotifier>;
     factories["pubrawtx"] = CZMQAbstractNotifier::Create<CZMQPublishRawTransactionNotifier>;
 
-    for (std::map<std::string, CZMQNotifierFactory>::const_iterator i=factories.begin(); i!=factories.end(); ++i)
+    for (const auto& entry : factories)
     {
-        std::string arg("-zmq" + i->first);
+        std::string arg("-zmq" + entry.first);
         if (gArgs.IsArgSet(arg))
         {
-            CZMQNotifierFactory factory = i->second;
+            CZMQNotifierFactory factory = entry.second;
             std::string address = gArgs.GetArg(arg, "");
             CZMQAbstractNotifier *notifier = factory();
-            notifier->SetType(i->first);
+            notifier->SetType(entry.first);
             notifier->SetAddress(address);
             notifiers.push_back(notifier);
         }