Merge #20480: Replace boost::variant with std::variant

faa8f68943 Replace boost::variant with std::variant (MarcoFalke)

Pull request description:

  Now that we can use std::variant from the vanilla standard library, drop the third-party boost variant dependency

ACKs for top commit:
  fjahr:
    Code review ACK faa8f68943
  fanquake:
    ACK faa8f68943

Tree-SHA512: 6e3aecd33b00c2e31a763f999247944d5b2ce5e3018f1965c516c1000cd08ff6703a8d50fb0be64883153da2925ae72986b8a6b96586db74057bd05d6f4986e6

src/key_io.cpp

@@ -8,16 +8,12 @@
 #include <bech32.h>
 #include <util/strencodings.h>
 
-#include <boost/variant/apply_visitor.hpp>
+#include <algorithm>
-#include <boost/variant/static_visitor.hpp>
-
 #include <assert.h>
 #include <string.h>
-#include <algorithm>
 
-namespace
+namespace {
-{
+class DestinationEncoder
-class DestinationEncoder : public boost::static_visitor<std::string>
 {
 private:
     const CChainParams& m_params;
@@ -209,7 +205,7 @@ std::string EncodeExtKey(const CExtKey& key)
 
 std::string EncodeDestination(const CTxDestination& dest)
 {
-    return boost::apply_visitor(DestinationEncoder(Params()), dest);
+    return std::visit(DestinationEncoder(Params()), dest);
 }
 
 CTxDestination DecodeDestination(const std::string& str)

src/qt/addresstablemodel.cpp

@@ -11,7 +11,6 @@
 #include <wallet/wallet.h>
 
 #include <algorithm>
-#include <typeinfo>
 
 #include <QFont>
 #include <QDebug>
@@ -82,8 +81,9 @@ public:
         {
             for (const auto& address : wallet.getAddresses())
             {
-                if (pk_hash_only && address.dest.type() != typeid(PKHash))
+                if (pk_hash_only && !std::holds_alternative<PKHash>(address.dest)) {
                     continue;
+                }
                 AddressTableEntry::Type addressType = translateTransactionType(
                         QString::fromStdString(address.purpose), address.is_mine);
                 cachedAddressTable.append(AddressTableEntry(addressType,
@@ -261,7 +261,7 @@ bool AddressTableModel::setData(const QModelIndex &index, const QVariant &value,
         } else if(index.column() == Address) {
             CTxDestination newAddress = DecodeDestination(value.toString().toStdString());
             // Refuse to set invalid address, set error status and return false
-            if(boost::get<CNoDestination>(&newAddress))
+            if(std::get_if<CNoDestination>(&newAddress))
             {
                 editStatus = INVALID_ADDRESS;
                 return false;

src/qt/coincontroldialog.cpp

@@ -455,7 +455,7 @@ void CoinControlDialog::updateLabels(CCoinControl& m_coin_control, WalletModel *
         else if(ExtractDestination(out.txout.scriptPubKey, address))
         {
             CPubKey pubkey;
-            PKHash *pkhash = boost::get<PKHash>(&address);
+            PKHash* pkhash = std::get_if<PKHash>(&address);
             if (pkhash && model->wallet().getPubKey(out.txout.scriptPubKey, ToKeyID(*pkhash), pubkey))
             {
                 nBytesInputs += (pubkey.IsCompressed() ? 148 : 180);

src/qt/signverifymessagedialog.cpp

@@ -120,7 +120,7 @@ void SignVerifyMessageDialog::on_signMessageButton_SM_clicked()
         ui->statusLabel_SM->setText(tr("The entered address is invalid.") + QString(" ") + tr("Please check the address and try again."));
         return;
     }
-    const PKHash* pkhash = boost::get<PKHash>(&destination);
+    const PKHash* pkhash = std::get_if<PKHash>(&destination);
     if (!pkhash) {
         ui->addressIn_SM->setValid(false);
         ui->statusLabel_SM->setStyleSheet("QLabel { color: red; }");

src/qt/transactionrecord.cpp

@@ -123,7 +123,7 @@ QList<TransactionRecord> TransactionRecord::decomposeTransaction(const interface
                     continue;
                 }
 
-                if (!boost::get<CNoDestination>(&wtx.txout_address[nOut]))
+                if (!std::get_if<CNoDestination>(&wtx.txout_address[nOut]))
                 {
                     // Sent to Bitcoin Address
                     sub.type = TransactionRecord::SendToAddress;

src/rpc/util.cpp

@@ -209,7 +209,7 @@ CTxDestination AddAndGetMultisigDestination(const int required, const std::vecto
     return dest;
 }
 
-class DescribeAddressVisitor : public boost::static_visitor<UniValue>
+class DescribeAddressVisitor
 {
 public:
     explicit DescribeAddressVisitor() {}
@@ -267,7 +267,7 @@ public:
 
 UniValue DescribeAddress(const CTxDestination& dest)
 {
-    return boost::apply_visitor(DescribeAddressVisitor(), dest);
+    return std::visit(DescribeAddressVisitor(), dest);
 }
 
 unsigned int ParseConfirmTarget(const UniValue& value, unsigned int max_target)

src/script/descriptor.cpp

@@ -565,7 +565,7 @@ public:
 
     Optional<OutputType> GetOutputType() const override
     {
-        switch (m_destination.which()) {
+        switch (m_destination.index()) {
             case 1 /* PKHash */:
             case 2 /* ScriptHash */: return OutputType::LEGACY;
             case 3 /* WitnessV0ScriptHash */:
@@ -593,7 +593,7 @@ public:
     {
         CTxDestination dest;
         ExtractDestination(m_script, dest);
-        switch (dest.which()) {
+        switch (dest.index()) {
             case 1 /* PKHash */:
             case 2 /* ScriptHash */: return OutputType::LEGACY;
             case 3 /* WitnessV0ScriptHash */:

src/script/signingprovider.cpp

@@ -179,18 +179,18 @@ CKeyID GetKeyForDestination(const SigningProvider& store, const CTxDestination&
 {
     // Only supports destinations which map to single public keys, i.e. P2PKH,
     // P2WPKH, and P2SH-P2WPKH.
-    if (auto id = boost::get<PKHash>(&dest)) {
+    if (auto id = std::get_if<PKHash>(&dest)) {
         return ToKeyID(*id);
     }
-    if (auto witness_id = boost::get<WitnessV0KeyHash>(&dest)) {
+    if (auto witness_id = std::get_if<WitnessV0KeyHash>(&dest)) {
         return ToKeyID(*witness_id);
     }
-    if (auto script_hash = boost::get<ScriptHash>(&dest)) {
+    if (auto script_hash = std::get_if<ScriptHash>(&dest)) {
         CScript script;
         CScriptID script_id(*script_hash);
         CTxDestination inner_dest;
         if (store.GetCScript(script_id, script) && ExtractDestination(script, inner_dest)) {
-            if (auto inner_witness_id = boost::get<WitnessV0KeyHash>(&inner_dest)) {
+            if (auto inner_witness_id = std::get_if<WitnessV0KeyHash>(&inner_dest)) {
                 return ToKeyID(*inner_witness_id);
             }
         }

src/script/standard.cpp

@@ -261,9 +261,8 @@ bool ExtractDestinations(const CScript& scriptPubKey, TxoutType& typeRet, std::v
     return true;
 }
 
-namespace
+namespace {
-{
+class CScriptVisitor
-class CScriptVisitor : public boost::static_visitor<CScript>
 {
 public:
     CScript operator()(const CNoDestination& dest) const
@@ -300,7 +299,7 @@ public:
 
 CScript GetScriptForDestination(const CTxDestination& dest)
 {
-    return boost::apply_visitor(CScriptVisitor(), dest);
+    return std::visit(CScriptVisitor(), dest);
 }
 
 CScript GetScriptForRawPubKey(const CPubKey& pubKey)
@@ -320,5 +319,5 @@ CScript GetScriptForMultisig(int nRequired, const std::vector<CPubKey>& keys)
 }
 
 bool IsValidDestination(const CTxDestination& dest) {
-    return dest.which() != 0;
+    return dest.index() != 0;
 }

src/script/standard.h

@@ -9,10 +9,8 @@
 #include <script/interpreter.h>
 #include <uint256.h>
 
-#include <boost/variant.hpp>
-
 #include <string>
-
+#include <variant>
 
 static const bool DEFAULT_ACCEPT_DATACARRIER = true;
 
@@ -211,7 +209,7 @@ struct WitnessUnknown
  *    (taproot outputs do not require their own type as long as no wallet support exists)
  *  A CTxDestination is the internal data type encoded in a bitcoin address
  */
-typedef boost::variant<CNoDestination, PKHash, ScriptHash, WitnessV0ScriptHash, WitnessV0KeyHash, WitnessUnknown> CTxDestination;
+using CTxDestination = std::variant<CNoDestination, PKHash, ScriptHash, WitnessV0ScriptHash, WitnessV0KeyHash, WitnessUnknown>;
 
 /** Check whether a CTxDestination is a CNoDestination. */
 bool IsValidDestination(const CTxDestination& dest);

src/test/script_standard_tests.cpp

@@ -183,23 +183,23 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestination)
     s.clear();
     s << ToByteVector(pubkey) << OP_CHECKSIG;
     BOOST_CHECK(ExtractDestination(s, address));
-    BOOST_CHECK(boost::get<PKHash>(&address) &&
+    BOOST_CHECK(std::get_if<PKHash>(&address) &&
-                *boost::get<PKHash>(&address) == PKHash(pubkey));
+                *std::get_if<PKHash>(&address) == PKHash(pubkey));
 
     // TxoutType::PUBKEYHASH
     s.clear();
     s << OP_DUP << OP_HASH160 << ToByteVector(pubkey.GetID()) << OP_EQUALVERIFY << OP_CHECKSIG;
     BOOST_CHECK(ExtractDestination(s, address));
-    BOOST_CHECK(boost::get<PKHash>(&address) &&
+    BOOST_CHECK(std::get_if<PKHash>(&address) &&
-                *boost::get<PKHash>(&address) == PKHash(pubkey));
+                *std::get_if<PKHash>(&address) == PKHash(pubkey));
 
     // TxoutType::SCRIPTHASH
     CScript redeemScript(s); // initialize with leftover P2PKH script
     s.clear();
     s << OP_HASH160 << ToByteVector(CScriptID(redeemScript)) << OP_EQUAL;
     BOOST_CHECK(ExtractDestination(s, address));
-    BOOST_CHECK(boost::get<ScriptHash>(&address) &&
+    BOOST_CHECK(std::get_if<ScriptHash>(&address) &&
-                *boost::get<ScriptHash>(&address) == ScriptHash(redeemScript));
+                *std::get_if<ScriptHash>(&address) == ScriptHash(redeemScript));
 
     // TxoutType::MULTISIG
     s.clear();
@@ -217,7 +217,7 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestination)
     BOOST_CHECK(ExtractDestination(s, address));
     WitnessV0KeyHash keyhash;
     CHash160().Write(pubkey).Finalize(keyhash);
-    BOOST_CHECK(boost::get<WitnessV0KeyHash>(&address) && *boost::get<WitnessV0KeyHash>(&address) == keyhash);
+    BOOST_CHECK(std::get_if<WitnessV0KeyHash>(&address) && *std::get_if<WitnessV0KeyHash>(&address) == keyhash);
 
     // TxoutType::WITNESS_V0_SCRIPTHASH
     s.clear();
@@ -225,7 +225,7 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestination)
     CSHA256().Write(redeemScript.data(), redeemScript.size()).Finalize(scripthash.begin());
     s << OP_0 << ToByteVector(scripthash);
     BOOST_CHECK(ExtractDestination(s, address));
-    BOOST_CHECK(boost::get<WitnessV0ScriptHash>(&address) && *boost::get<WitnessV0ScriptHash>(&address) == scripthash);
+    BOOST_CHECK(std::get_if<WitnessV0ScriptHash>(&address) && *std::get_if<WitnessV0ScriptHash>(&address) == scripthash);
 
     // TxoutType::WITNESS_UNKNOWN with unknown version
     s.clear();
@@ -235,7 +235,7 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestination)
     unk.length = 33;
     unk.version = 1;
     std::copy(pubkey.begin(), pubkey.end(), unk.program);
-    BOOST_CHECK(boost::get<WitnessUnknown>(&address) && *boost::get<WitnessUnknown>(&address) == unk);
+    BOOST_CHECK(std::get_if<WitnessUnknown>(&address) && *std::get_if<WitnessUnknown>(&address) == unk);
 }
 
 BOOST_AUTO_TEST_CASE(script_standard_ExtractDestinations)
@@ -259,8 +259,8 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestinations)
     BOOST_CHECK_EQUAL(whichType, TxoutType::PUBKEY);
     BOOST_CHECK_EQUAL(addresses.size(), 1U);
     BOOST_CHECK_EQUAL(nRequired, 1);
-    BOOST_CHECK(boost::get<PKHash>(&addresses[0]) &&
+    BOOST_CHECK(std::get_if<PKHash>(&addresses[0]) &&
-                *boost::get<PKHash>(&addresses[0]) == PKHash(pubkeys[0]));
+                *std::get_if<PKHash>(&addresses[0]) == PKHash(pubkeys[0]));
 
     // TxoutType::PUBKEYHASH
     s.clear();
@@ -269,8 +269,8 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestinations)
     BOOST_CHECK_EQUAL(whichType, TxoutType::PUBKEYHASH);
     BOOST_CHECK_EQUAL(addresses.size(), 1U);
     BOOST_CHECK_EQUAL(nRequired, 1);
-    BOOST_CHECK(boost::get<PKHash>(&addresses[0]) &&
+    BOOST_CHECK(std::get_if<PKHash>(&addresses[0]) &&
-                *boost::get<PKHash>(&addresses[0]) == PKHash(pubkeys[0]));
+                *std::get_if<PKHash>(&addresses[0]) == PKHash(pubkeys[0]));
 
     // TxoutType::SCRIPTHASH
     CScript redeemScript(s); // initialize with leftover P2PKH script
@@ -280,8 +280,8 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestinations)
     BOOST_CHECK_EQUAL(whichType, TxoutType::SCRIPTHASH);
     BOOST_CHECK_EQUAL(addresses.size(), 1U);
     BOOST_CHECK_EQUAL(nRequired, 1);
-    BOOST_CHECK(boost::get<ScriptHash>(&addresses[0]) &&
+    BOOST_CHECK(std::get_if<ScriptHash>(&addresses[0]) &&
-                *boost::get<ScriptHash>(&addresses[0]) == ScriptHash(redeemScript));
+                *std::get_if<ScriptHash>(&addresses[0]) == ScriptHash(redeemScript));
 
     // TxoutType::MULTISIG
     s.clear();
@@ -293,10 +293,10 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestinations)
     BOOST_CHECK_EQUAL(whichType, TxoutType::MULTISIG);
     BOOST_CHECK_EQUAL(addresses.size(), 2U);
     BOOST_CHECK_EQUAL(nRequired, 2);
-    BOOST_CHECK(boost::get<PKHash>(&addresses[0]) &&
+    BOOST_CHECK(std::get_if<PKHash>(&addresses[0]) &&
-                *boost::get<PKHash>(&addresses[0]) == PKHash(pubkeys[0]));
+                *std::get_if<PKHash>(&addresses[0]) == PKHash(pubkeys[0]));
-    BOOST_CHECK(boost::get<PKHash>(&addresses[1]) &&
+    BOOST_CHECK(std::get_if<PKHash>(&addresses[1]) &&
-                *boost::get<PKHash>(&addresses[1]) == PKHash(pubkeys[1]));
+                *std::get_if<PKHash>(&addresses[1]) == PKHash(pubkeys[1]));
 
     // TxoutType::NULL_DATA
     s.clear();

src/util/message.cpp

@@ -31,7 +31,7 @@ MessageVerificationResult MessageVerify(
         return MessageVerificationResult::ERR_INVALID_ADDRESS;
     }
 
-    if (boost::get<PKHash>(&destination) == nullptr) {
+    if (std::get_if<PKHash>(&destination) == nullptr) {
         return MessageVerificationResult::ERR_ADDRESS_NO_KEY;
     }
 

src/wallet/rpcwallet.cpp

@@ -627,7 +627,7 @@ static RPCHelpMan signmessage()
         throw JSONRPCError(RPC_TYPE_ERROR, "Invalid address");
     }
 
-    const PKHash *pkhash = boost::get<PKHash>(&dest);
+    const PKHash* pkhash = std::get_if<PKHash>(&dest);
     if (!pkhash) {
         throw JSONRPCError(RPC_TYPE_ERROR, "Address does not refer to key");
     }
@@ -3002,7 +3002,7 @@ static RPCHelpMan listunspent()
             std::unique_ptr<SigningProvider> provider = pwallet->GetSolvingProvider(scriptPubKey);
             if (provider) {
                 if (scriptPubKey.IsPayToScriptHash()) {
-                    const CScriptID& hash = CScriptID(boost::get<ScriptHash>(address));
+                    const CScriptID& hash = CScriptID(std::get<ScriptHash>(address));
                     CScript redeemScript;
                     if (provider->GetCScript(hash, redeemScript)) {
                         entry.pushKV("redeemScript", HexStr(redeemScript));
@@ -3012,7 +3012,7 @@ static RPCHelpMan listunspent()
                             bool extracted = ExtractDestination(redeemScript, witness_destination);
                             CHECK_NONFATAL(extracted);
                             // Also return the witness script
-                            const WitnessV0ScriptHash& whash = boost::get<WitnessV0ScriptHash>(witness_destination);
+                            const WitnessV0ScriptHash& whash = std::get<WitnessV0ScriptHash>(witness_destination);
                             CScriptID id;
                             CRIPEMD160().Write(whash.begin(), whash.size()).Finalize(id.begin());
                             CScript witnessScript;
@@ -3022,7 +3022,7 @@ static RPCHelpMan listunspent()
                         }
                     }
                 } else if (scriptPubKey.IsPayToWitnessScriptHash()) {
-                    const WitnessV0ScriptHash& whash = boost::get<WitnessV0ScriptHash>(address);
+                    const WitnessV0ScriptHash& whash = std::get<WitnessV0ScriptHash>(address);
                     CScriptID id;
                     CRIPEMD160().Write(whash.begin(), whash.size()).Finalize(id.begin());
                     CScript witnessScript;
@@ -3645,7 +3645,7 @@ static RPCHelpMan rescanblockchain()
     };
 }
 
-class DescribeWalletAddressVisitor : public boost::static_visitor<UniValue>
+class DescribeWalletAddressVisitor
 {
 public:
     const SigningProvider * const provider;
@@ -3664,7 +3664,7 @@ public:
             UniValue subobj(UniValue::VOBJ);
             UniValue detail = DescribeAddress(embedded);
             subobj.pushKVs(detail);
-            UniValue wallet_detail = boost::apply_visitor(*this, embedded);
+            UniValue wallet_detail = std::visit(*this, embedded);
             subobj.pushKVs(wallet_detail);
             subobj.pushKV("address", EncodeDestination(embedded));
             subobj.pushKV("scriptPubKey", HexStr(subscript));
@@ -3747,7 +3747,7 @@ static UniValue DescribeWalletAddress(const CWallet* const pwallet, const CTxDes
         provider = pwallet->GetSolvingProvider(script);
     }
     ret.pushKVs(detail);
-    ret.pushKVs(boost::apply_visitor(DescribeWalletAddressVisitor(provider.get()), dest));
+    ret.pushKVs(std::visit(DescribeWalletAddressVisitor(provider.get()), dest));
     return ret;
 }
 

src/wallet/test/wallet_tests.cpp

@@ -550,7 +550,7 @@ BOOST_FIXTURE_TEST_CASE(ListCoins, ListCoinsTestingSetup)
         list = wallet->ListCoins();
     }
     BOOST_CHECK_EQUAL(list.size(), 1U);
-    BOOST_CHECK_EQUAL(boost::get<PKHash>(list.begin()->first).ToString(), coinbaseAddress);
+    BOOST_CHECK_EQUAL(std::get<PKHash>(list.begin()->first).ToString(), coinbaseAddress);
     BOOST_CHECK_EQUAL(list.begin()->second.size(), 1U);
 
     // Check initial balance from one mature coinbase transaction.
@@ -566,7 +566,7 @@ BOOST_FIXTURE_TEST_CASE(ListCoins, ListCoinsTestingSetup)
         list = wallet->ListCoins();
     }
     BOOST_CHECK_EQUAL(list.size(), 1U);
-    BOOST_CHECK_EQUAL(boost::get<PKHash>(list.begin()->first).ToString(), coinbaseAddress);
+    BOOST_CHECK_EQUAL(std::get<PKHash>(list.begin()->first).ToString(), coinbaseAddress);
     BOOST_CHECK_EQUAL(list.begin()->second.size(), 2U);
 
     // Lock both coins. Confirm number of available coins drops to 0.
@@ -595,7 +595,7 @@ BOOST_FIXTURE_TEST_CASE(ListCoins, ListCoinsTestingSetup)
         list = wallet->ListCoins();
     }
     BOOST_CHECK_EQUAL(list.size(), 1U);
-    BOOST_CHECK_EQUAL(boost::get<PKHash>(list.begin()->first).ToString(), coinbaseAddress);
+    BOOST_CHECK_EQUAL(std::get<PKHash>(list.begin()->first).ToString(), coinbaseAddress);
     BOOST_CHECK_EQUAL(list.begin()->second.size(), 2U);
 }
 

src/wallet/wallet.cpp

@@ -2789,7 +2789,7 @@ bool CWallet::CreateTransactionInternal(
             CScript scriptChange;
 
             // coin control: send change to custom address
-            if (!boost::get<CNoDestination>(&coin_control.destChange)) {
+            if (!std::get_if<CNoDestination>(&coin_control.destChange)) {
                 scriptChange = GetScriptForDestination(coin_control.destChange);
             } else { // no coin control: send change to newly generated address
                 // Note: We use a new key here to keep it from being obvious which side is the change.
@@ -3724,7 +3724,7 @@ unsigned int CWallet::ComputeTimeSmart(const CWalletTx& wtx) const
 
 bool CWallet::AddDestData(WalletBatch& batch, const CTxDestination &dest, const std::string &key, const std::string &value)
 {
-    if (boost::get<CNoDestination>(&dest))
+    if (std::get_if<CNoDestination>(&dest))
         return false;
 
     m_address_book[dest].destdata.insert(std::make_pair(key, value));

test/lint/lint-includes.sh

@@ -71,9 +71,6 @@ EXPECTED_BOOST_INCLUDES=(
     boost/thread/mutex.hpp
     boost/thread/shared_mutex.hpp
     boost/thread/thread.hpp
-    boost/variant.hpp
-    boost/variant/apply_visitor.hpp
-    boost/variant/static_visitor.hpp
 )
 
 for BOOST_INCLUDE in $(git grep '^#include <boost/' -- "*.cpp" "*.h" | cut -f2 -d: | cut -f2 -d'<' | cut -f1 -d'>' | sort -u); do