Merge #19114: scripted-diff: TxoutType C++11 scoped enum class

fa32adf9dc25540ad27f5b82654c7057d7738627 scripted-diff: TxoutType C++11 scoped enum class (MarcoFalke)
fa95a694c492b267e4038674fd3f338dd215ab48 doc: Update outdated txnouttype documentation (MarcoFalke)
fa58469c770d8c935a86462634e4e8cd806aa6e3 rpc: Properly use underlying type in GetAllOutputTypes (MarcoFalke)
fa41c657022b8f99c8e6718a0e33c5838c412a0b rpc: Simplify GetAllOutputTypes with the Join helper (MarcoFalke)

Pull request description:

  Non-scoped enums can accidentally and silently decay into an integral type. Also, the symbol names of the keys are exported to the surrounding (usually global) namespace.

  Fix both issues by switching to an `enum class TxoutType` in a (mostly) scripted-diff.

ACKs for top commit:
  practicalswift:
    ACK fa32adf9dc25540ad27f5b82654c7057d7738627 -- patch looks correct
  hebasto:
    re-ACK fa32adf9dc25540ad27f5b82654c7057d7738627, since fa5997bd6fc82e16b597ea96e3c5c665f1f174ab (https://github.com/bitcoin/bitcoin/pull/19114#pullrequestreview-421425198) rebased only (verified with `git range-diff`).

Tree-SHA512: f42a9db47f9be89fa4bdd8d2fb05a16726286d8b12e3d87327b67d723f91c7d5a57deb4b2ddae9e1d16fee7a5f8c00828b6dc8909c5db680fc5e0a3cf07cd465

4 files changed, 92 insertions, 93 deletions

diff --git a/src/script/descriptor.cpp b/src/script/descriptor.cpp
index 2634d3ad4f..5fa128d62d 100644
--- a/src/script/descriptor.cpp
+++ b/src/script/descriptor.cpp
@@ -985,15 +985,15 @@ std::unique_ptr<PubkeyProvider> InferPubkey(const CPubKey& pubkey, ParseScriptCo
 std::unique_ptr<DescriptorImpl> InferScript(const CScript& script, ParseScriptContext ctx, const SigningProvider& provider)
 {
     std::vector<std::vector<unsigned char>> data;
-    txnouttype txntype = Solver(script, data);
+    TxoutType txntype = Solver(script, data);
 
-    if (txntype == TX_PUBKEY) {
+    if (txntype == TxoutType::PUBKEY) {
         CPubKey pubkey(data[0].begin(), data[0].end());
         if (pubkey.IsValid()) {
             return MakeUnique<PKDescriptor>(InferPubkey(pubkey, ctx, provider));
         }
     }
-    if (txntype == TX_PUBKEYHASH) {
+    if (txntype == TxoutType::PUBKEYHASH) {
         uint160 hash(data[0]);
         CKeyID keyid(hash);
         CPubKey pubkey;
@@ -1001,7 +1001,7 @@ std::unique_ptr<DescriptorImpl> InferScript(const CScript& script, ParseScriptCo
             return MakeUnique<PKHDescriptor>(InferPubkey(pubkey, ctx, provider));
         }
     }
-    if (txntype == TX_WITNESS_V0_KEYHASH && ctx != ParseScriptContext::P2WSH) {
+    if (txntype == TxoutType::WITNESS_V0_KEYHASH && ctx != ParseScriptContext::P2WSH) {
         uint160 hash(data[0]);
         CKeyID keyid(hash);
         CPubKey pubkey;
@@ -1009,7 +1009,7 @@ std::unique_ptr<DescriptorImpl> InferScript(const CScript& script, ParseScriptCo
             return MakeUnique<WPKHDescriptor>(InferPubkey(pubkey, ctx, provider));
         }
     }
-    if (txntype == TX_MULTISIG) {
+    if (txntype == TxoutType::MULTISIG) {
         std::vector<std::unique_ptr<PubkeyProvider>> providers;
         for (size_t i = 1; i + 1 < data.size(); ++i) {
             CPubKey pubkey(data[i].begin(), data[i].end());
@@ -1017,7 +1017,7 @@ std::unique_ptr<DescriptorImpl> InferScript(const CScript& script, ParseScriptCo
         }
         return MakeUnique<MultisigDescriptor>((int)data[0][0], std::move(providers));
     }
-    if (txntype == TX_SCRIPTHASH && ctx == ParseScriptContext::TOP) {
+    if (txntype == TxoutType::SCRIPTHASH && ctx == ParseScriptContext::TOP) {
         uint160 hash(data[0]);
         CScriptID scriptid(hash);
         CScript subscript;
@@ -1026,7 +1026,7 @@ std::unique_ptr<DescriptorImpl> InferScript(const CScript& script, ParseScriptCo
             if (sub) return MakeUnique<SHDescriptor>(std::move(sub));
         }
     }
-    if (txntype == TX_WITNESS_V0_SCRIPTHASH && ctx != ParseScriptContext::P2WSH) {
+    if (txntype == TxoutType::WITNESS_V0_SCRIPTHASH && ctx != ParseScriptContext::P2WSH) {
         CScriptID scriptid;
         CRIPEMD160().Write(data[0].data(), data[0].size()).Finalize(scriptid.begin());
         CScript subscript;
diff --git a/src/script/sign.cpp b/src/script/sign.cpp
index 43988c4fd7..f425215549 100644
--- a/src/script/sign.cpp
+++ b/src/script/sign.cpp
@@ -92,11 +92,11 @@ static bool CreateSig(const BaseSignatureCreator& creator, SignatureData& sigdat
 /**
  * Sign scriptPubKey using signature made with creator.
  * Signatures are returned in scriptSigRet (or returns false if scriptPubKey can't be signed),
- * unless whichTypeRet is TX_SCRIPTHASH, in which case scriptSigRet is the redemption script.
+ * unless whichTypeRet is TxoutType::SCRIPTHASH, in which case scriptSigRet is the redemption script.
  * Returns false if scriptPubKey could not be completely satisfied.
  */
 static bool SignStep(const SigningProvider& provider, const BaseSignatureCreator& creator, const CScript& scriptPubKey,
-                     std::vector<valtype>& ret, txnouttype& whichTypeRet, SigVersion sigversion, SignatureData& sigdata)
+                     std::vector<valtype>& ret, TxoutType& whichTypeRet, SigVersion sigversion, SignatureData& sigdata)
 {
     CScript scriptRet;
     uint160 h160;
@@ -108,15 +108,15 @@ static bool SignStep(const SigningProvider& provider, const BaseSignatureCreator
 
     switch (whichTypeRet)
     {
-    case TX_NONSTANDARD:
-    case TX_NULL_DATA:
-    case TX_WITNESS_UNKNOWN:
+    case TxoutType::NONSTANDARD:
+    case TxoutType::NULL_DATA:
+    case TxoutType::WITNESS_UNKNOWN:
         return false;
-    case TX_PUBKEY:
+    case TxoutType::PUBKEY:
         if (!CreateSig(creator, sigdata, provider, sig, CPubKey(vSolutions[0]), scriptPubKey, sigversion)) return false;
         ret.push_back(std::move(sig));
         return true;
-    case TX_PUBKEYHASH: {
+    case TxoutType::PUBKEYHASH: {
         CKeyID keyID = CKeyID(uint160(vSolutions[0]));
         CPubKey pubkey;
         if (!GetPubKey(provider, sigdata, keyID, pubkey)) {
@@ -129,7 +129,7 @@ static bool SignStep(const SigningProvider& provider, const BaseSignatureCreator
         ret.push_back(ToByteVector(pubkey));
         return true;
     }
-    case TX_SCRIPTHASH:
+    case TxoutType::SCRIPTHASH:
         h160 = uint160(vSolutions[0]);
         if (GetCScript(provider, sigdata, CScriptID{h160}, scriptRet)) {
             ret.push_back(std::vector<unsigned char>(scriptRet.begin(), scriptRet.end()));
@@ -139,7 +139,7 @@ static bool SignStep(const SigningProvider& provider, const BaseSignatureCreator
         sigdata.missing_redeem_script = h160;
         return false;
 
-    case TX_MULTISIG: {
+    case TxoutType::MULTISIG: {
         size_t required = vSolutions.front()[0];
         ret.push_back(valtype()); // workaround CHECKMULTISIG bug
         for (size_t i = 1; i < vSolutions.size() - 1; ++i) {
@@ -159,11 +159,11 @@ static bool SignStep(const SigningProvider& provider, const BaseSignatureCreator
         }
         return ok;
     }
-    case TX_WITNESS_V0_KEYHASH:
+    case TxoutType::WITNESS_V0_KEYHASH:
         ret.push_back(vSolutions[0]);
         return true;
 
-    case TX_WITNESS_V0_SCRIPTHASH:
+    case TxoutType::WITNESS_V0_SCRIPTHASH:
         CRIPEMD160().Write(&vSolutions[0][0], vSolutions[0].size()).Finalize(h160.begin());
         if (GetCScript(provider, sigdata, CScriptID{h160}, scriptRet)) {
             ret.push_back(std::vector<unsigned char>(scriptRet.begin(), scriptRet.end()));
@@ -198,44 +198,44 @@ bool ProduceSignature(const SigningProvider& provider, const BaseSignatureCreato
     if (sigdata.complete) return true;
 
     std::vector<valtype> result;
-    txnouttype whichType;
+    TxoutType whichType;
     bool solved = SignStep(provider, creator, fromPubKey, result, whichType, SigVersion::BASE, sigdata);
     bool P2SH = false;
     CScript subscript;
     sigdata.scriptWitness.stack.clear();
 
-    if (solved && whichType == TX_SCRIPTHASH)
+    if (solved && whichType == TxoutType::SCRIPTHASH)
     {
         // Solver returns the subscript that needs to be evaluated;
         // the final scriptSig is the signatures from that
         // and then the serialized subscript:
         subscript = CScript(result[0].begin(), result[0].end());
         sigdata.redeem_script = subscript;
-        solved = solved && SignStep(provider, creator, subscript, result, whichType, SigVersion::BASE, sigdata) && whichType != TX_SCRIPTHASH;
+        solved = solved && SignStep(provider, creator, subscript, result, whichType, SigVersion::BASE, sigdata) && whichType != TxoutType::SCRIPTHASH;
         P2SH = true;
     }
 
-    if (solved && whichType == TX_WITNESS_V0_KEYHASH)
+    if (solved && whichType == TxoutType::WITNESS_V0_KEYHASH)
     {
         CScript witnessscript;
         witnessscript << OP_DUP << OP_HASH160 << ToByteVector(result[0]) << OP_EQUALVERIFY << OP_CHECKSIG;
-        txnouttype subType;
+        TxoutType subType;
         solved = solved && SignStep(provider, creator, witnessscript, result, subType, SigVersion::WITNESS_V0, sigdata);
         sigdata.scriptWitness.stack = result;
         sigdata.witness = true;
         result.clear();
     }
-    else if (solved && whichType == TX_WITNESS_V0_SCRIPTHASH)
+    else if (solved && whichType == TxoutType::WITNESS_V0_SCRIPTHASH)
     {
         CScript witnessscript(result[0].begin(), result[0].end());
         sigdata.witness_script = witnessscript;
-        txnouttype subType;
-        solved = solved && SignStep(provider, creator, witnessscript, result, subType, SigVersion::WITNESS_V0, sigdata) && subType != TX_SCRIPTHASH && subType != TX_WITNESS_V0_SCRIPTHASH && subType != TX_WITNESS_V0_KEYHASH;
+        TxoutType subType;
+        solved = solved && SignStep(provider, creator, witnessscript, result, subType, SigVersion::WITNESS_V0, sigdata) && subType != TxoutType::SCRIPTHASH && subType != TxoutType::WITNESS_V0_SCRIPTHASH && subType != TxoutType::WITNESS_V0_KEYHASH;
         result.push_back(std::vector<unsigned char>(witnessscript.begin(), witnessscript.end()));
         sigdata.scriptWitness.stack = result;
         sigdata.witness = true;
         result.clear();
-    } else if (solved && whichType == TX_WITNESS_UNKNOWN) {
+    } else if (solved && whichType == TxoutType::WITNESS_UNKNOWN) {
         sigdata.witness = true;
     }
 
@@ -301,11 +301,11 @@ SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nI
 
     // Get scripts
     std::vector<std::vector<unsigned char>> solutions;
-    txnouttype script_type = Solver(txout.scriptPubKey, solutions);
+    TxoutType script_type = Solver(txout.scriptPubKey, solutions);
     SigVersion sigversion = SigVersion::BASE;
     CScript next_script = txout.scriptPubKey;
 
-    if (script_type == TX_SCRIPTHASH && !stack.script.empty() && !stack.script.back().empty()) {
+    if (script_type == TxoutType::SCRIPTHASH && !stack.script.empty() && !stack.script.back().empty()) {
         // Get the redeemScript
         CScript redeem_script(stack.script.back().begin(), stack.script.back().end());
         data.redeem_script = redeem_script;
@@ -315,7 +315,7 @@ SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nI
         script_type = Solver(next_script, solutions);
         stack.script.pop_back();
     }
-    if (script_type == TX_WITNESS_V0_SCRIPTHASH && !stack.witness.empty() && !stack.witness.back().empty()) {
+    if (script_type == TxoutType::WITNESS_V0_SCRIPTHASH && !stack.witness.empty() && !stack.witness.back().empty()) {
         // Get the witnessScript
         CScript witness_script(stack.witness.back().begin(), stack.witness.back().end());
         data.witness_script = witness_script;
@@ -328,7 +328,7 @@ SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nI
         stack.witness.clear();
         sigversion = SigVersion::WITNESS_V0;
     }
-    if (script_type == TX_MULTISIG && !stack.script.empty()) {
+    if (script_type == TxoutType::MULTISIG && !stack.script.empty()) {
         // Build a map of pubkey -> signature by matching sigs to pubkeys:
         assert(solutions.size() > 1);
         unsigned int num_pubkeys = solutions.size()-2;
@@ -454,13 +454,13 @@ bool IsSegWitOutput(const SigningProvider& provider, const CScript& script)
 {
     std::vector<valtype> solutions;
     auto whichtype = Solver(script, solutions);
-    if (whichtype == TX_WITNESS_V0_SCRIPTHASH || whichtype == TX_WITNESS_V0_KEYHASH || whichtype == TX_WITNESS_UNKNOWN) return true;
-    if (whichtype == TX_SCRIPTHASH) {
+    if (whichtype == TxoutType::WITNESS_V0_SCRIPTHASH || whichtype == TxoutType::WITNESS_V0_KEYHASH || whichtype == TxoutType::WITNESS_UNKNOWN) return true;
+    if (whichtype == TxoutType::SCRIPTHASH) {
         auto h160 = uint160(solutions[0]);
         CScript subscript;
         if (provider.GetCScript(CScriptID{h160}, subscript)) {
             whichtype = Solver(subscript, solutions);
-            if (whichtype == TX_WITNESS_V0_SCRIPTHASH || whichtype == TX_WITNESS_V0_KEYHASH || whichtype == TX_WITNESS_UNKNOWN) return true;
+            if (whichtype == TxoutType::WITNESS_V0_SCRIPTHASH || whichtype == TxoutType::WITNESS_V0_KEYHASH || whichtype == TxoutType::WITNESS_UNKNOWN) return true;
         }
     }
     return false;
diff --git a/src/script/standard.cpp b/src/script/standard.cpp
index 2adf6ce56d..39dd4ff39f 100644
--- a/src/script/standard.cpp
+++ b/src/script/standard.cpp
@@ -43,20 +43,20 @@ WitnessV0ScriptHash::WitnessV0ScriptHash(const CScript& in)
     CSHA256().Write(in.data(), in.size()).Finalize(begin());
 }
 
-std::string GetTxnOutputType(txnouttype t)
+std::string GetTxnOutputType(TxoutType t)
 {
     switch (t)
     {
-    case TX_NONSTANDARD: return "nonstandard";
-    case TX_PUBKEY: return "pubkey";
-    case TX_PUBKEYHASH: return "pubkeyhash";
-    case TX_SCRIPTHASH: return "scripthash";
-    case TX_MULTISIG: return "multisig";
-    case TX_NULL_DATA: return "nulldata";
-    case TX_WITNESS_V0_KEYHASH: return "witness_v0_keyhash";
-    case TX_WITNESS_V0_SCRIPTHASH: return "witness_v0_scripthash";
-    case TX_WITNESS_UNKNOWN: return "witness_unknown";
-    }
+    case TxoutType::NONSTANDARD: return "nonstandard";
+    case TxoutType::PUBKEY: return "pubkey";
+    case TxoutType::PUBKEYHASH: return "pubkeyhash";
+    case TxoutType::SCRIPTHASH: return "scripthash";
+    case TxoutType::MULTISIG: return "multisig";
+    case TxoutType::NULL_DATA: return "nulldata";
+    case TxoutType::WITNESS_V0_KEYHASH: return "witness_v0_keyhash";
+    case TxoutType::WITNESS_V0_SCRIPTHASH: return "witness_v0_scripthash";
+    case TxoutType::WITNESS_UNKNOWN: return "witness_unknown";
+    } // no default case, so the compiler can warn about missing cases
     assert(false);
 }
 
@@ -106,7 +106,7 @@ static bool MatchMultisig(const CScript& script, unsigned int& required, std::ve
     return (it + 1 == script.end());
 }
 
-txnouttype Solver(const CScript& scriptPubKey, std::vector<std::vector<unsigned char>>& vSolutionsRet)
+TxoutType Solver(const CScript& scriptPubKey, std::vector<std::vector<unsigned char>>& vSolutionsRet)
 {
     vSolutionsRet.clear();
 
@@ -116,7 +116,7 @@ txnouttype Solver(const CScript& scriptPubKey, std::vector<std::vector<unsigned
     {
         std::vector<unsigned char> hashBytes(scriptPubKey.begin()+2, scriptPubKey.begin()+22);
         vSolutionsRet.push_back(hashBytes);
-        return TX_SCRIPTHASH;
+        return TxoutType::SCRIPTHASH;
     }
 
     int witnessversion;
@@ -124,18 +124,18 @@ txnouttype Solver(const CScript& scriptPubKey, std::vector<std::vector<unsigned
     if (scriptPubKey.IsWitnessProgram(witnessversion, witnessprogram)) {
         if (witnessversion == 0 && witnessprogram.size() == WITNESS_V0_KEYHASH_SIZE) {
             vSolutionsRet.push_back(witnessprogram);
-            return TX_WITNESS_V0_KEYHASH;
+            return TxoutType::WITNESS_V0_KEYHASH;
         }
         if (witnessversion == 0 && witnessprogram.size() == WITNESS_V0_SCRIPTHASH_SIZE) {
             vSolutionsRet.push_back(witnessprogram);
-            return TX_WITNESS_V0_SCRIPTHASH;
+            return TxoutType::WITNESS_V0_SCRIPTHASH;
         }
         if (witnessversion != 0) {
             vSolutionsRet.push_back(std::vector<unsigned char>{(unsigned char)witnessversion});
             vSolutionsRet.push_back(std::move(witnessprogram));
-            return TX_WITNESS_UNKNOWN;
+            return TxoutType::WITNESS_UNKNOWN;
         }
-        return TX_NONSTANDARD;
+        return TxoutType::NONSTANDARD;
     }
 
     // Provably prunable, data-carrying output
@@ -144,18 +144,18 @@ txnouttype Solver(const CScript& scriptPubKey, std::vector<std::vector<unsigned
     // byte passes the IsPushOnly() test we don't care what exactly is in the
     // script.
     if (scriptPubKey.size() >= 1 && scriptPubKey[0] == OP_RETURN && scriptPubKey.IsPushOnly(scriptPubKey.begin()+1)) {
-        return TX_NULL_DATA;
+        return TxoutType::NULL_DATA;
     }
 
     std::vector<unsigned char> data;
     if (MatchPayToPubkey(scriptPubKey, data)) {
         vSolutionsRet.push_back(std::move(data));
-        return TX_PUBKEY;
+        return TxoutType::PUBKEY;
     }
 
     if (MatchPayToPubkeyHash(scriptPubKey, data)) {
         vSolutionsRet.push_back(std::move(data));
-        return TX_PUBKEYHASH;
+        return TxoutType::PUBKEYHASH;
     }
 
     unsigned int required;
@@ -164,19 +164,19 @@ txnouttype Solver(const CScript& scriptPubKey, std::vector<std::vector<unsigned
         vSolutionsRet.push_back({static_cast<unsigned char>(required)}); // safe as required is in range 1..16
         vSolutionsRet.insert(vSolutionsRet.end(), keys.begin(), keys.end());
         vSolutionsRet.push_back({static_cast<unsigned char>(keys.size())}); // safe as size is in range 1..16
-        return TX_MULTISIG;
+        return TxoutType::MULTISIG;
     }
 
     vSolutionsRet.clear();
-    return TX_NONSTANDARD;
+    return TxoutType::NONSTANDARD;
 }
 
 bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
 {
     std::vector<valtype> vSolutions;
-    txnouttype whichType = Solver(scriptPubKey, vSolutions);
+    TxoutType whichType = Solver(scriptPubKey, vSolutions);
 
-    if (whichType == TX_PUBKEY) {
+    if (whichType == TxoutType::PUBKEY) {
         CPubKey pubKey(vSolutions[0]);
         if (!pubKey.IsValid())
             return false;
@@ -184,26 +184,26 @@ bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
         addressRet = PKHash(pubKey);
         return true;
     }
-    else if (whichType == TX_PUBKEYHASH)
+    else if (whichType == TxoutType::PUBKEYHASH)
     {
         addressRet = PKHash(uint160(vSolutions[0]));
         return true;
     }
-    else if (whichType == TX_SCRIPTHASH)
+    else if (whichType == TxoutType::SCRIPTHASH)
     {
         addressRet = ScriptHash(uint160(vSolutions[0]));
         return true;
-    } else if (whichType == TX_WITNESS_V0_KEYHASH) {
+    } else if (whichType == TxoutType::WITNESS_V0_KEYHASH) {
         WitnessV0KeyHash hash;
         std::copy(vSolutions[0].begin(), vSolutions[0].end(), hash.begin());
         addressRet = hash;
         return true;
-    } else if (whichType == TX_WITNESS_V0_SCRIPTHASH) {
+    } else if (whichType == TxoutType::WITNESS_V0_SCRIPTHASH) {
         WitnessV0ScriptHash hash;
         std::copy(vSolutions[0].begin(), vSolutions[0].end(), hash.begin());
         addressRet = hash;
         return true;
-    } else if (whichType == TX_WITNESS_UNKNOWN) {
+    } else if (whichType == TxoutType::WITNESS_UNKNOWN) {
         WitnessUnknown unk;
         unk.version = vSolutions[0][0];
         std::copy(vSolutions[1].begin(), vSolutions[1].end(), unk.program);
@@ -215,19 +215,19 @@ bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
     return false;
 }
 
-bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet)
+bool ExtractDestinations(const CScript& scriptPubKey, TxoutType& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet)
 {
     addressRet.clear();
     std::vector<valtype> vSolutions;
     typeRet = Solver(scriptPubKey, vSolutions);
-    if (typeRet == TX_NONSTANDARD) {
+    if (typeRet == TxoutType::NONSTANDARD) {
         return false;
-    } else if (typeRet == TX_NULL_DATA) {
+    } else if (typeRet == TxoutType::NULL_DATA) {
         // This is data, not addresses
         return false;
     }
 
-    if (typeRet == TX_MULTISIG)
+    if (typeRet == TxoutType::MULTISIG)
     {
         nRequiredRet = vSolutions.front()[0];
         for (unsigned int i = 1; i < vSolutions.size()-1; i++)
@@ -319,10 +319,10 @@ CScript GetScriptForMultisig(int nRequired, const std::vector<CPubKey>& keys)
 CScript GetScriptForWitness(const CScript& redeemscript)
 {
     std::vector<std::vector<unsigned char> > vSolutions;
-    txnouttype typ = Solver(redeemscript, vSolutions);
-    if (typ == TX_PUBKEY) {
+    TxoutType typ = Solver(redeemscript, vSolutions);
+    if (typ == TxoutType::PUBKEY) {
         return GetScriptForDestination(WitnessV0KeyHash(Hash160(vSolutions[0].begin(), vSolutions[0].end())));
-    } else if (typ == TX_PUBKEYHASH) {
+    } else if (typ == TxoutType::PUBKEYHASH) {
         return GetScriptForDestination(WitnessV0KeyHash(uint160{vSolutions[0]}));
     }
     return GetScriptForDestination(WitnessV0ScriptHash(redeemscript));
diff --git a/src/script/standard.h b/src/script/standard.h
index 4baed6da6e..fd29353886 100644
--- a/src/script/standard.h
+++ b/src/script/standard.h
@@ -99,11 +99,11 @@ static const unsigned int MAX_OP_RETURN_RELAY = 83;
 
 /**
  * A data carrying output is an unspendable output containing data. The script
- * type is designated as TX_NULL_DATA.
+ * type is designated as TxoutType::NULL_DATA.
  */
 extern bool fAcceptDatacarrier;
 
-/** Maximum size of TX_NULL_DATA scripts that this node considers standard. */
+/** Maximum size of TxoutType::NULL_DATA scripts that this node considers standard. */
 extern unsigned nMaxDatacarrierBytes;
 
 /**
@@ -116,18 +116,17 @@ extern unsigned nMaxDatacarrierBytes;
  */
 static const unsigned int MANDATORY_SCRIPT_VERIFY_FLAGS = SCRIPT_VERIFY_P2SH;
 
-enum txnouttype
-{
-    TX_NONSTANDARD,
+enum class TxoutType {
+    NONSTANDARD,
     // 'standard' transaction types:
-    TX_PUBKEY,
-    TX_PUBKEYHASH,
-    TX_SCRIPTHASH,
-    TX_MULTISIG,
-    TX_NULL_DATA, //!< unspendable OP_RETURN script that carries data
-    TX_WITNESS_V0_SCRIPTHASH,
-    TX_WITNESS_V0_KEYHASH,
-    TX_WITNESS_UNKNOWN, //!< Only for Witness versions not already defined above
+    PUBKEY,
+    PUBKEYHASH,
+    SCRIPTHASH,
+    MULTISIG,
+    NULL_DATA, //!< unspendable OP_RETURN script that carries data
+    WITNESS_V0_SCRIPTHASH,
+    WITNESS_V0_KEYHASH,
+    WITNESS_UNKNOWN, //!< Only for Witness versions not already defined above
 };
 
 class CNoDestination {
@@ -200,11 +199,11 @@ struct WitnessUnknown
 /**
  * A txout script template with a specific destination. It is either:
  *  * CNoDestination: no destination set
- *  * PKHash: TX_PUBKEYHASH destination (P2PKH)
- *  * ScriptHash: TX_SCRIPTHASH destination (P2SH)
- *  * WitnessV0ScriptHash: TX_WITNESS_V0_SCRIPTHASH destination (P2WSH)
- *  * WitnessV0KeyHash: TX_WITNESS_V0_KEYHASH destination (P2WPKH)
- *  * WitnessUnknown: TX_WITNESS_UNKNOWN destination (P2W???)
+ *  * PKHash: TxoutType::PUBKEYHASH destination (P2PKH)
+ *  * ScriptHash: TxoutType::SCRIPTHASH destination (P2SH)
+ *  * WitnessV0ScriptHash: TxoutType::WITNESS_V0_SCRIPTHASH destination (P2WSH)
+ *  * WitnessV0KeyHash: TxoutType::WITNESS_V0_KEYHASH destination (P2WPKH)
+ *  * WitnessUnknown: TxoutType::WITNESS_UNKNOWN destination (P2W???)
  *  A CTxDestination is the internal data type encoded in a bitcoin address
  */
 typedef boost::variant<CNoDestination, PKHash, ScriptHash, WitnessV0ScriptHash, WitnessV0KeyHash, WitnessUnknown> CTxDestination;
@@ -212,8 +211,8 @@ typedef boost::variant<CNoDestination, PKHash, ScriptHash, WitnessV0ScriptHash,
 /** Check whether a CTxDestination is a CNoDestination. */
 bool IsValidDestination(const CTxDestination& dest);
 
-/** Get the name of a txnouttype as a C string, or nullptr if unknown. */
-std::string GetTxnOutputType(txnouttype t);
+/** Get the name of a TxoutType as a string */
+std::string GetTxnOutputType(TxoutType t);
 
 /**
  * Parse a scriptPubKey and identify script type for standard scripts. If
@@ -223,9 +222,9 @@ std::string GetTxnOutputType(txnouttype t);
  *
  * @param[in]   scriptPubKey   Script to parse
  * @param[out]  vSolutionsRet  Vector of parsed pubkeys and hashes
- * @return                     The script type. TX_NONSTANDARD represents a failed solve.
+ * @return                     The script type. TxoutType::NONSTANDARD represents a failed solve.
  */
-txnouttype Solver(const CScript& scriptPubKey, std::vector<std::vector<unsigned char>>& vSolutionsRet);
+TxoutType Solver(const CScript& scriptPubKey, std::vector<std::vector<unsigned char>>& vSolutionsRet);
 
 /**
  * Parse a standard scriptPubKey for the destination address. Assigns result to
@@ -246,7 +245,7 @@ bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
  * encodable as an address) with key identifiers (of keys involved in a
  * CScript), and its use should be phased out.
  */
-bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet);
+bool ExtractDestinations(const CScript& scriptPubKey, TxoutType& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet);
 
 /**
  * Generate a Bitcoin scriptPubKey for the given CTxDestination. Returns a P2PKH