Don't use pass by reference to const for cheaply-copied types (bool,

char, etc.).

src/legacy/validation_zerocoin_legacy.cpp

@@ -59,7 +59,7 @@ void DataBaseAccChecksum(const CBlockIndex* pindex, bool fWrite)
     arith_uint256 accPrev = UintToArith256(pindex->pprev->nAccumulatorCheckpoint);
     // add/remove changed checksums to/from DB
     for (int i = (int)libzerocoin::zerocoinDenomList.size()-1; i >= 0; i--) {
-        const uint32_t& nChecksum = accCurr.Get32();
+        const uint32_t nChecksum = accCurr.Get32();
         if (nChecksum != accPrev.Get32()) {
             fWrite ?
             zerocoinDB->WriteAccChecksum(nChecksum, libzerocoin::zerocoinDenomList[i], pindex->nHeight) :

src/qt/pivx/coldstakingmodel.cpp

@@ -72,7 +72,7 @@ void ColdStakingModel::refresh()
     }
 }
 
-bool ColdStakingModel::parseCSDelegation(const CTxOut& out, CSDelegation& ret, const QString& txId, const int& utxoIndex)
+bool ColdStakingModel::parseCSDelegation(const CTxOut& out, CSDelegation& ret, const QString& txId, const int utxoIndex)
 {
     txnouttype type;
     std::vector<CTxDestination> addresses;

src/qt/pivx/coldstakingmodel.h

@@ -86,7 +86,7 @@ public Q_SLOTS:
     QList<CSDelegation> cachedDelegations;
     CAmount cachedAmount;
 
-    bool parseCSDelegation(const CTxOut& out, CSDelegation& ret, const QString& txId, const int& utxoIndex);
+    bool parseCSDelegation(const CTxOut& out, CSDelegation& ret, const QString& txId, const int utxoIndex);
 };
 
 #endif // COLDSTAKINGMODEL_H

src/qt/pivx/coldstakingwidget.cpp

@@ -228,7 +228,7 @@ void ColdStakingWidget::loadWalletModel()
 
 }
 
-void ColdStakingWidget::onTxArrived(const QString& hash, const bool& isCoinStake, const bool& isCSAnyType)
+void ColdStakingWidget::onTxArrived(const QString& hash, const bool isCoinStake, const bool isCSAnyType)
 {
     if (isCSAnyType) {
         tryRefreshDelegations();
@@ -732,7 +732,7 @@ void ColdStakingWidget::onLabelClicked()
     );
 }
 
-void ColdStakingWidget::onLabelClicked(QString dialogTitle, const QModelIndex &index, const bool& isMyColdStakingAddresses)
+void ColdStakingWidget::onLabelClicked(QString dialogTitle, const QModelIndex &index, const bool isMyColdStakingAddresses)
 {
     if (walletModel && !isShowingDialog) {
         isShowingDialog = true;

src/qt/pivx/coldstakingwidget.h

@@ -69,7 +69,7 @@ private Q_SLOTS:
     void onCopyOwnerClicked();
     void onAddressCopyClicked();
     void onAddressEditClicked();
-    void onTxArrived(const QString& hash, const bool& isCoinStake, const bool& isCSAnyType);
+    void onTxArrived(const QString& hash, const bool isCoinStake, const bool isCSAnyType);
     void onContactsClicked(bool ownerAdd);
     void clearAll();
     void onLabelClicked();
@@ -121,7 +121,7 @@ private Q_SLOTS:
     void onContactsClicked();
     void tryRefreshDelegations();
     bool refreshDelegations();
-    void onLabelClicked(QString dialogTitle, const QModelIndex &index, const bool& isMyColdStakingAddresses);
+    void onLabelClicked(QString dialogTitle, const QModelIndex &index, const bool isMyColdStakingAddresses);
     void updateStakingTotalLabel();
     void sortAddresses();
     void setCoinControlPayAmounts();

src/qt/pivx/dashboardwidget.cpp

@@ -220,7 +220,7 @@ void DashboardWidget::loadWalletModel()
     updateDisplayUnit();
 }
 
-void DashboardWidget::onTxArrived(const QString& hash, const bool& isCoinStake, const bool& isCSAnyType)
+void DashboardWidget::onTxArrived(const QString& hash, const bool isCoinStake, const bool isCSAnyType)
 {
     showList();
     if (!isVisible()) return;

src/qt/pivx/dashboardwidget.h

@@ -122,7 +122,7 @@ private Q_SLOTS:
     void onSortTypeChanged(const QString& value);
     void updateDisplayUnit();
     void showList();
-    void onTxArrived(const QString& hash, const bool& isCoinStake, const bool& isCSAnyType);
+    void onTxArrived(const QString& hash, const bool isCoinStake, const bool isCSAnyType);
 
 #ifdef USE_QTCHARTS
     void windowResizeEvent(QResizeEvent* event);

src/qt/pivx/settings/settingsexportcsv.cpp

@@ -55,7 +55,7 @@ SettingsExportCSV::SettingsExportCSV(PIVXGUI* _window, QWidget *parent) :
     connect(ui->pushButtonAddressDocuments, &QPushButton::clicked, [this](){selectFileOutput(false);});
 }
 
-void SettingsExportCSV::selectFileOutput(const bool& isTxExport)
+void SettingsExportCSV::selectFileOutput(const bool isTxExport)
 {
     QString filename = GUIUtil::getSaveFileName(this,
                                         isTxExport ? tr("Export CSV") : tr("Export Address List"), QString(),

src/qt/pivx/settings/settingsexportcsv.h

@@ -23,7 +23,7 @@ class SettingsExportCSV : public PWidget
     ~SettingsExportCSV();
 
 private Q_SLOTS:
-    void selectFileOutput(const bool& isTxExport);
+    void selectFileOutput(const bool isTxExport);
     void exportTxes(const QString& filename);
     void exportAddrs(const QString& filename);
 

src/qt/pivx/topbar.cpp

@@ -702,7 +702,7 @@ void TopBar::expandSync()
     }
 }
 
-void TopBar::updateHDState(const bool& upgraded, const QString& upgradeError)
+void TopBar::updateHDState(const bool upgraded, const QString& upgradeError)
 {
     if (upgraded) {
         ui->pushButtonHDUpgrade->setVisible(false);

src/qt/pivx/topbar.h

@@ -51,7 +51,7 @@ public Q_SLOTS:
     void setNumBlocks(int count);
     void setStakingStatusActive(bool fActive);
     void updateStakingStatus();
-    void updateHDState(const bool& upgraded, const QString& upgradeError);
+    void updateHDState(const bool upgraded, const QString& upgradeError);
     void showUpgradeDialog(const QString& message);
 
 Q_SIGNALS:

src/qt/transactiontablemodel.h

@@ -83,7 +83,7 @@ class TransactionTableModel : public QAbstractTableModel
     bool processingQueuedTransactions() const { return fProcessingQueuedTransactions; }
 
 Q_SIGNALS:
-    void txArrived(const QString& hash, const bool& isCoinStake, const bool& isCSAnyType);
+    void txArrived(const QString& hash, const bool isCoinStake, const bool isCSAnyType);
 
 private:
     // Listeners

src/qt/walletmodel.cpp

@@ -804,7 +804,7 @@ static void NotifySSTChanged(WalletModel* walletmodel, const CAmount stakeSplitT
     Q_EMIT walletmodel->notifySSTChanged(val);
 }
 
-static void NotifyWalletBacked(WalletModel* model, const bool& fSuccess, const std::string& filename)
+static void NotifyWalletBacked(WalletModel* model, const bool fSuccess, const std::string& filename)
 {
     std::string message;
     std::string title = "Backup ";

src/streams.h

@@ -130,8 +130,8 @@ class CBaseDataStream
         vch.clear();
         nReadPos = 0;
     }
-    iterator insert(iterator it, const char& x = char()) { return vch.insert(it, x); }
-    void insert(iterator it, size_type n, const char& x) { vch.insert(it, n, x); }
+    iterator insert(iterator it, const char x = char()) { return vch.insert(it, x); }
+    void insert(iterator it, size_type n, const char x) { vch.insert(it, n, x); }
     value_type* data()                               { return vch.data() + nReadPos; }
     const value_type* data() const                   { return vch.data() + nReadPos; }
 

src/txdb.cpp

@@ -383,17 +383,17 @@ bool CZerocoinDB::EraseCoinSpend(const CBigNum& bnSerial)
 static const char LZC_ACCUMCS = 'A';
 //static const char LZC_MAPSUPPLY = 'M'; // TODO: add removal for LZC_MAPSUPPLY key-value if is found in db
 
-bool CZerocoinDB::WriteAccChecksum(const uint32_t& nChecksum, const libzerocoin::CoinDenomination denom, const int nHeight)
+bool CZerocoinDB::WriteAccChecksum(const uint32_t nChecksum, const libzerocoin::CoinDenomination denom, const int nHeight)
 {
     return Write(std::make_pair(LZC_ACCUMCS, std::make_pair(nChecksum, denom)), nHeight);
 }
 
-bool CZerocoinDB::ReadAccChecksum(const uint32_t& nChecksum, const libzerocoin::CoinDenomination denom, int& nHeightRet)
+bool CZerocoinDB::ReadAccChecksum(const uint32_t nChecksum, const libzerocoin::CoinDenomination denom, int& nHeightRet)
 {
     return Read(std::make_pair(LZC_ACCUMCS, std::make_pair(nChecksum, denom)), nHeightRet);
 }
 
-bool CZerocoinDB::EraseAccChecksum(const uint32_t& nChecksum, const libzerocoin::CoinDenomination denom)
+bool CZerocoinDB::EraseAccChecksum(const uint32_t nChecksum, const libzerocoin::CoinDenomination denom)
 {
     return Erase(std::make_pair(LZC_ACCUMCS, std::make_pair(nChecksum, denom)));
 }

src/txdb.h

@@ -166,9 +166,9 @@ class CZerocoinDB : public CDBWrapper
     bool EraseCoinSpend(const CBigNum& bnSerial);
 
     /** Accumulators (only for zPoS IBD): [checksum, denom] --> block height **/
-    bool WriteAccChecksum(const uint32_t& nChecksum, const libzerocoin::CoinDenomination denom, const int nHeight);
-    bool ReadAccChecksum(const uint32_t& nChecksum, const libzerocoin::CoinDenomination denom, int& nHeightRet);
-    bool EraseAccChecksum(const uint32_t& nChecksum, const libzerocoin::CoinDenomination denom);
+    bool WriteAccChecksum(const uint32_t nChecksum, const libzerocoin::CoinDenomination denom, const int nHeight);
+    bool ReadAccChecksum(const uint32_t nChecksum, const libzerocoin::CoinDenomination denom, int& nHeightRet);
+    bool EraseAccChecksum(const uint32_t nChecksum, const libzerocoin::CoinDenomination denom);
     bool WipeAccChecksums();
 };
 

src/wallet/rpcdump.cpp

@@ -665,8 +665,8 @@ static UniValue processImport(CWallet* const pwallet, const UniValue& data, cons
         const std::string& strRedeemScript = data.exists("redeemscript") ? data["redeemscript"].get_str() : "";
         const UniValue& pubKeys = data.exists("pubkeys") ? data["pubkeys"].get_array() : UniValue();
         const UniValue& keys = data.exists("keys") ? data["keys"].get_array() : UniValue();
-        const bool& internal = data.exists("internal") ? data["internal"].get_bool() : false;
-        const bool& watchOnly = data.exists("watchonly") ? data["watchonly"].get_bool() : false;
+        const bool internal = data.exists("internal") ? data["internal"].get_bool() : false;
+        const bool watchOnly = data.exists("watchonly") ? data["watchonly"].get_bool() : false;
         const std::string& label = data.exists("label") && !internal ? data["label"].get_str() : "";
 
         bool isScript = scriptPubKey.getType() == UniValue::VSTR;

src/wallet/scriptpubkeyman.cpp

@@ -20,7 +20,7 @@ bool ScriptPubKeyMan::SetupGeneration(bool newKeypool, bool force, bool memOnly)
     return true;
 }
 
-bool ScriptPubKeyMan::Upgrade(const int& prev_version, std::string& error)
+bool ScriptPubKeyMan::Upgrade(const int prev_version, std::string& error)
 {
     LOCK(wallet->cs_KeyStore);
     error = "";

src/wallet/scriptpubkeyman.h

@@ -38,7 +38,7 @@ class ScriptPubKeyMan {
     bool SetupGeneration(bool newKeypool = true, bool force = false, bool memOnly = false);
 
     /** Upgrades the wallet to the specified version */
-    bool Upgrade(const int& prev_version, std::string& error);
+    bool Upgrade(const int prev_version, std::string& error);
 
     /* Returns true if the wallet can generate new keys */
     bool CanGenerateKeys();

src/wallet/wallet.cpp

@@ -1736,7 +1736,7 @@ CAmount CWalletTx::GetLockedCredit() const
     return nCredit;
 }
 
-CAmount CWalletTx::GetImmatureWatchOnlyCredit(const bool& fUseCache) const
+CAmount CWalletTx::GetImmatureWatchOnlyCredit(const bool fUseCache) const
 {
     if (IsInMainChainImmature()) {
         return GetCachableAmount(IMMATURE_CREDIT, ISMINE_WATCH_ONLY, !fUseCache);
@@ -1745,7 +1745,7 @@ CAmount CWalletTx::GetImmatureWatchOnlyCredit(const bool& fUseCache) const
     return 0;
 }
 
-CAmount CWalletTx::GetAvailableWatchOnlyCredit(const bool& fUseCache) const
+CAmount CWalletTx::GetAvailableWatchOnlyCredit(const bool fUseCache) const
 {
     return GetAvailableCredit(fUseCache, ISMINE_WATCH_ONLY);
 }
@@ -1820,7 +1820,7 @@ void CWalletTx::GetAmounts(std::list<COutputEntry>& listReceived,
     }
 }
 
-bool CWallet::Upgrade(std::string& error, const int& prevVersion)
+bool CWallet::Upgrade(std::string& error, const int prevVersion)
 {
     LOCK2(cs_wallet, cs_KeyStore);
 
@@ -3611,7 +3611,7 @@ void CWallet::KeepKey(int64_t nIndex)
     m_spk_man->KeepDestination(nIndex);
 }
 
-void CWallet::ReturnKey(int64_t nIndex, const bool& internal, const bool& staking)
+void CWallet::ReturnKey(int64_t nIndex, const bool internal, const bool staking)
 {
     // Return to key pool
     CTxDestination address; // This is not needed for now.

src/wallet/wallet.h

@@ -489,8 +489,8 @@ class CWalletTx
     CAmount GetAvailableCredit(bool fUseCache = true, const isminefilter& filter=ISMINE_SPENDABLE) const;
     // Return sum of locked coins
     CAmount GetLockedCredit() const;
-    CAmount GetImmatureWatchOnlyCredit(const bool& fUseCache = true) const;
-    CAmount GetAvailableWatchOnlyCredit(const bool& fUseCache = true) const;
+    CAmount GetImmatureWatchOnlyCredit(const bool fUseCache = true) const;
+    CAmount GetAvailableWatchOnlyCredit(const bool fUseCache = true) const;
     CAmount GetChange() const;
 
     // Shielded credit/debit/change
@@ -1004,7 +1004,7 @@ class CWallet : public CCryptoKeyStore, public CValidationInterface
     /**
      * Upgrade wallet to HD and Sapling if needed. Does nothing if not.
      */
-    bool Upgrade(std::string& error, const int& prevVersion);
+    bool Upgrade(std::string& error, const int prevVersion);
     bool ActivateSaplingWallet(bool memOnly = false);
 
     int64_t RescanFromTime(int64_t startTime, const WalletRescanReserver& reserver, bool update);
@@ -1094,7 +1094,7 @@ class CWallet : public CCryptoKeyStore, public CValidationInterface
     size_t KeypoolCountExternalKeys();
     bool TopUpKeyPool(unsigned int kpSize = 0);
     void KeepKey(int64_t nIndex);
-    void ReturnKey(int64_t nIndex, const bool& internal = false, const bool& staking = false);
+    void ReturnKey(int64_t nIndex, const bool internal = false, const bool staking = false);
     bool GetKeyFromPool(CPubKey& key, const uint8_t& type = HDChain::ChangeType::EXTERNAL);
     int64_t GetOldestKeyPoolTime();
 
@@ -1207,7 +1207,7 @@ class CWallet : public CCryptoKeyStore, public CValidationInterface
     boost::signals2::signal<void(bool fHaveWatchOnly)> NotifyWatchonlyChanged;
 
     /** notify wallet file backed up */
-    boost::signals2::signal<void (const bool& fSuccess, const std::string& filename)> NotifyWalletBacked;
+    boost::signals2::signal<void (const bool fSuccess, const std::string& filename)> NotifyWalletBacked;
 
     /** notify stake-split threshold changed */
     boost::signals2::signal<void (const CAmount stakeSplitThreshold)> NotifySSTChanged;