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) {
  }

Cherry-picked from: 953f620

src/addrman.cpp

@@ -390,9 +390,9 @@ 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

@@ -313,18 +313,18 @@ 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;
@@ -437,13 +437,13 @@ class CAddrMan
 
         // Prune new entries with refcount 0 (as a result of collisions).
         int nLostUnk = 0;
-        for (std::map<int, CAddrInfo>::const_iterator it = mapInfo.begin(); it != mapInfo.end(); ) {
-            if (it->second.fInTried == false && it->second.nRefCount == 0) {
-                std::map<int, CAddrInfo>::const_iterator itCopy = it++;
-                Delete(itCopy->first);
+        for (const auto& entry : mapInfo) {
+            if (entry.second.fInTried == false && entry.second.nRefCount == 0) {
+                std::pair<const int, CAddrInfo> itCopy = entry;
+                Delete(itCopy.first);
                 nLostUnk++;
             } else {
-                it++;
+                continue;
             }
         }
         if (nLost + nLostUnk > 0) {

src/net.cpp

@@ -100,13 +100,13 @@ 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++)
+        for (const auto& entry : mapLocalHost)
         {
-            int nScore = (*it).second.nScore;
-            int nReachability = (*it).first.GetReachabilityFrom(paddrPeer);
+            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

@@ -54,11 +54,11 @@ 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/qt/transactiontablemodel.cpp

@@ -84,10 +84,10 @@ class TransactionTablePriv
         cachedWallet.clear();
         {
             LOCK2(cs_main, wallet->cs_wallet);
-            for(std::map<uint256, CWalletTx>::iterator it = wallet->mapWallet.begin(); it != wallet->mapWallet.end(); ++it)
+            for (const auto& entry : wallet->mapWallet)
             {
-                if(TransactionRecord::showTransaction(it->second))
-                    cachedWallet.append(TransactionRecord::decomposeTransaction(wallet, it->second));
+                if (TransactionRecord::showTransaction(entry.second))
+                    cachedWallet.append(TransactionRecord::decomposeTransaction(wallet, entry.second));
             }
         }
     }

src/rpc/net.cpp

@@ -596,14 +596,14 @@ 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());
+        // rec.pushKV("ban_reason", banEntry.banReasonToString()); // TODO
 
         bannedAddresses.push_back(rec);
     }

src/serialize.h

@@ -725,8 +725,8 @@ 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

@@ -77,8 +77,10 @@ class CCoinsViewCacheTest : public CCoinsViewCache
     {
         // Manually recompute the dynamic usage of the whole data, and compare it.
         size_t ret = memusage::DynamicUsage(cacheCoins);
-        for (CCoinsMap::iterator it = cacheCoins.begin(); it != cacheCoins.end(); it++) {
-            ret += it->second.coins.DynamicMemoryUsage();
+        size_t count = 0;
+        for (const auto& entry : cacheCoins) {
+            ret += entry.second.coins.DynamicMemoryUsage();
+            ++count;
         }
         BOOST_CHECK_EQUAL(DynamicMemoryUsage(), ret);
     }
@@ -154,13 +156,13 @@ 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 (std::map<uint256, CCoins>::iterator it = result.begin(); it != result.end(); it++) {
-                const CCoins* coins = stack.back()->AccessCoins(it->first);
+            for (const auto& entry : result) {
+                const CCoins* coins = stack.back()->AccessCoins(entry.first);
                 if (coins) {
-                    BOOST_CHECK(*coins == it->second);
+                    BOOST_CHECK(*coins == entry.second);
                     found_an_entry = true;
                 } else {
-                    BOOST_CHECK(it->second.IsPruned());
+                    BOOST_CHECK(entry.second.IsPruned());
                     missed_an_entry = true;
                 }
             }
@@ -385,12 +387,12 @@ 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 (std::map<uint256, CCoins>::iterator it = result.begin(); it != result.end(); it++) {
-                const CCoins* coins = stack.back()->AccessCoins(it->first);
+            for (const auto& entry : result) {
+                const CCoins* coins = stack.back()->AccessCoins(entry.first);
                 if (coins) {
-                    BOOST_CHECK(*coins == it->second);
+                    BOOST_CHECK(*coins == entry.second);
                 } else {
-                    BOOST_CHECK(it->second.IsPruned());
+                    BOOST_CHECK(entry.second.IsPruned());
                 }
             }
         }

src/validation.cpp

@@ -3460,8 +3460,8 @@ void PruneOneBlockFile(const int fileNumber)
 {
     LOCK(cs_LastBlockFile);
 
-    for (BlockMap::iterator it = mapBlockIndex.begin(); it != mapBlockIndex.end(); ++it) {
-        CBlockIndex* pindex = it->second;
+    for (const auto& entry : mapBlockIndex) {
+        CBlockIndex* pindex = entry.second;
         if (pindex->nFile == fileNumber) {
             pindex->nStatus &= ~BLOCK_HAVE_DATA;
             pindex->nStatus &= ~BLOCK_HAVE_UNDO;
@@ -3897,8 +3897,8 @@ bool RewindBlockIndex(const CChainParams& params)
     // Reduce validity flag and have-data flags.
     // We do this after actual disconnecting, otherwise we'll end up writing the lack of data
     // to disk before writing the chainstate, resulting in a failure to continue if interrupted.
-    for (BlockMap::iterator it = mapBlockIndex.begin(); it != mapBlockIndex.end(); it++) {
-        CBlockIndex* pindexIter = it->second;
+    for (const auto& entry : mapBlockIndex) {
+        CBlockIndex* pindexIter = entry.second;
 
         // Note: If we encounter an insufficiently validated block that
         // is on chainActive, it must be because we are a pruning node, and
@@ -4158,8 +4158,8 @@ void static CheckBlockIndex(const Consensus::Params& consensusParams)
 
     // 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.insert(std::make_pair(it->second->pprev, it->second));
+    for (auto& entry : mapBlockIndex) {
+        forward.insert(std::make_pair(entry.second->pprev, entry.second));
     }
 
     assert(forward.size() == mapBlockIndex.size());

src/wallet/rpcwallet.cpp

@@ -1327,14 +1327,14 @@ UniValue ListReceived(const UniValue& params, bool fByAccounts)
 
     if (fByAccounts)
     {
-        for (map<string, tallyitem>::iterator it = mapAccountTally.begin(); it != mapAccountTally.end(); ++it)
+        for (const auto& entry : mapAccountTally)
         {
-            CAmount nAmount = (*it).second.nAmount;
-            int nConf = (*it).second.nConf;
+            CAmount nAmount = entry.second.nAmount;
+            int nConf = entry.second.nConf;
             UniValue obj(UniValue::VOBJ);
-            if((*it).second.fIsWatchonly)
+            if(entry.second.fIsWatchonly)
                 obj.pushKV("involvesWatchonly", true);
-            obj.pushKV("account",       (*it).first);
+            obj.pushKV("account",       entry.first);
             obj.pushKV("amount",        ValueFromAmount(nAmount));
             obj.pushKV("confirmations", (nConf == std::numeric_limits<int>::max() ? 0 : nConf));
             ret.push_back(obj);

src/wallet/wallet.cpp

@@ -700,10 +700,10 @@ DBErrors CWallet::ReorderTransactions()
     typedef multimap<int64_t, TxPair > TxItems;
     TxItems txByTime;
 
-    for (map<uint256, CWalletTx>::iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
+    for (auto& entry : mapWallet)
     {
-        CWalletTx* wtx = &((*it).second);
-        txByTime.insert(make_pair(wtx->nTimeReceived, TxPair(wtx, (CAccountingEntry*)0)));
+        CWalletTx* wtx = &entry.second;
+        txByTime.insert(std::make_pair(wtx->nTimeReceived, TxPair(wtx, (CAccountingEntry*)0)));
     }
     list<CAccountingEntry> acentries;
     walletdb.ListAccountCreditDebit("", acentries);
@@ -1905,9 +1905,9 @@ CAmount CWallet::GetBalance() const
     CAmount nTotal = 0;
     {
         LOCK2(cs_main, cs_wallet);
-        for (map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
+        for (const auto& entry : mapWallet)
         {
-            const CWalletTx* pcoin = &(*it).second;
+            const CWalletTx* pcoin = &entry.second;
             if (pcoin->IsTrusted())
                 nTotal += pcoin->GetAvailableCredit();
         }
@@ -1921,9 +1921,9 @@ CAmount CWallet::GetUnconfirmedBalance() const
     CAmount nTotal = 0;
     {
         LOCK2(cs_main, cs_wallet);
-        for (map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
+        for (const auto& entry : mapWallet)
         {
-            const CWalletTx* pcoin = &(*it).second;
+            const CWalletTx* pcoin = &entry.second;
             if (!pcoin->IsTrusted() && pcoin->GetDepthInMainChain() == 0 && pcoin->InMempool())
                 nTotal += pcoin->GetAvailableCredit();
         }
@@ -1936,9 +1936,9 @@ CAmount CWallet::GetImmatureBalance() const
     CAmount nTotal = 0;
     {
         LOCK2(cs_main, cs_wallet);
-        for (map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
+        for (const auto& entry : mapWallet)
         {
-            const CWalletTx* pcoin = &(*it).second;
+            const CWalletTx* pcoin = &entry.second;
             nTotal += pcoin->GetImmatureCredit();
         }
     }
@@ -1950,9 +1950,9 @@ CAmount CWallet::GetWatchOnlyBalance() const
     CAmount nTotal = 0;
     {
         LOCK2(cs_main, cs_wallet);
-        for (map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
+        for (const auto& entry : mapWallet)
         {
-            const CWalletTx* pcoin = &(*it).second;
+            const CWalletTx* pcoin = &entry.second;
             if (pcoin->IsTrusted())
                 nTotal += pcoin->GetAvailableWatchOnlyCredit();
         }
@@ -1966,9 +1966,9 @@ CAmount CWallet::GetUnconfirmedWatchOnlyBalance() const
     CAmount nTotal = 0;
     {
         LOCK2(cs_main, cs_wallet);
-        for (map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
+        for (const auto& entry : mapWallet)
         {
-            const CWalletTx* pcoin = &(*it).second;
+            const CWalletTx* pcoin = &entry.second;
             if (!pcoin->IsTrusted() && pcoin->GetDepthInMainChain() == 0 && pcoin->InMempool())
                 nTotal += pcoin->GetAvailableWatchOnlyCredit();
         }
@@ -1981,9 +1981,9 @@ CAmount CWallet::GetImmatureWatchOnlyBalance() const
     CAmount nTotal = 0;
     {
         LOCK2(cs_main, cs_wallet);
-        for (map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
+        for (const auto& entry : mapWallet)
         {
-            const CWalletTx* pcoin = &(*it).second;
+            const CWalletTx* pcoin = &entry.second;
             nTotal += pcoin->GetImmatureWatchOnlyCredit();
         }
     }
@@ -1999,10 +1999,10 @@ void CWallet::AvailableCoins(vector<COutput> &vCoins, bool fOnlyConfirmed, const
 
         CAmount nTotal = 0;
 
-        for (map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
+        for (const auto& entry : mapWallet)
         {
-            const uint256& wtxid = it->first;
-            const CWalletTx* pcoin = &(*it).second;
+            const uint256& wtxid = entry.first;
+            const CWalletTx* pcoin = &entry.second;
 
             if (!CheckFinalTx(*pcoin))
                 continue;
@@ -2060,10 +2060,10 @@ void CWallet::AvailableCoins(vector<COutput> &vCoins, bool fOnlyConfirmed, const
                 if (pcoin->tx->vout[i].nValue < nMinimumAmount || pcoin->tx->vout[i].nValue > nMaximumAmount)
                     continue;
 
-                if (coinControl && coinControl->HasSelected() && !coinControl->fAllowOtherInputs && !coinControl->IsSelected(COutPoint((*it).first, i)))
+                if (coinControl && coinControl->HasSelected() && !coinControl->fAllowOtherInputs && !coinControl->IsSelected(COutPoint(entry.first, i)))
                     continue;
 
-                if (IsLockedCoin((*it).first, i))
+                if (IsLockedCoin(entry.first, i))
                     continue;
 
                 if (IsSpent(wtxid, i))
@@ -3571,9 +3571,9 @@ void CWallet::GetKeyBirthTimes(std::map<CTxDestination, int64_t> &mapKeyBirth) c
 
     // 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.hashBlock);
         if (blit != mapBlockIndex.end() && chainActive.Contains(blit->second)) {
             // ... which are already in a block
@@ -3593,8 +3593,8 @@ void CWallet::GetKeyBirthTimes(std::map<CTxDestination, int64_t> &mapKeyBirth) c
     }
 
     // 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() - 7200; // block times can be 2h off
+    for (const auto& entry : mapKeyFirstBlock)
+        mapKeyBirth[entry.first] = entry.second->GetBlockTime() - 7200; // block times can be 2h off
 }
 
 bool CWallet::AddDestData(const CTxDestination &dest, const std::string &key, const std::string &value)

src/zmq/zmqnotificationinterface.cpp

@@ -40,15 +40,15 @@ 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 (IsArgSet(arg))
         {
-            CZMQNotifierFactory factory = i->second;
+            CZMQNotifierFactory factory = entry.second;
             std::string address = GetArg(arg, "");
             CZMQAbstractNotifier *notifier = factory();
-            notifier->SetType(i->first);
+            notifier->SetType(entry.first);
             notifier->SetAddress(address);
             notifiers.push_back(notifier);
         }