message: refactor: Make CScriptVisitor stateless
diff: @@ -241,59 +241,47 @@ bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, std::
  namespace
  {
  -class CScriptVisitor : public boost::static_visitor<bool>
  +class CScriptVisitor : public boost::static_visitor<CScript>
  {
  -private:
  - CScript *script;
  public:
  - explicit CScriptVisitor(CScript *scriptin) { script = scriptin; }
  -
  - bool operator()(const CNoDestination &dest) const {
  - script->clear();
  - return false;
  + CScript operator()(const CNoDestination& dest) const
  + {
  + return CScript();
  }
  - bool operator()(const PKHash &keyID) const {
  - script->clear();
  - *script << OP_DUP << OP_HASH160 << ToByteVector(keyID) << OP_EQUALVERIFY << OP_CHECKSIG;
  - return true;
  + CScript operator()(const PKHash& keyID) const
  + {
  + return CScript() << OP_DUP << OP_HASH160 << ToByteVector(keyID) << OP_EQUALVERIFY << OP_CHECKSIG;
  }
  - bool operator()(const ScriptHash &scriptID) const {
  - script->clear();
  - *script << OP_HASH160 << ToByteVector(scriptID) << OP_EQUAL;
  - return true;
  + CScript operator()(const ScriptHash& scriptID) const
  + {
  + return CScript() << OP_HASH160 << ToByteVector(scriptID) << OP_EQUAL;
  }
  - bool operator()(const WitnessV0KeyHash& id) const
  + CScript operator()(const WitnessV0KeyHash& id) const
  {
  - script->clear();
  - *script << OP_0 << ToByteVector(id);
  - return true;
  + return CScript() << OP_0 << ToByteVector(id);
  }
  - bool operator()(const WitnessV0ScriptHash& id) const
  + CScript operator()(const WitnessV0ScriptHash& id) const
  {
  - script->clear();
  - *script << OP_0 << ToByteVector(id);
  - return true;
  + return CScript() << OP_0 << ToByteVector(id);
  }
  - bool operator()(const WitnessUnknown& id) const
  + CScript operator()(const WitnessUnknown& id) const
  {
  - script->clear();
  - *script << CScript::EncodeOP_N(id.version) << std::vector<unsigned char>(id.program, id.program + id.length);
  - return true;
  + return CScript() << CScript::EncodeOP_N(id.version) << std::vector<unsigned char>(id.program, id.program + id.length);
  }
  };
  +
  +const CScriptVisitor g_script_visitor;
  +
  } // namespace
  CScript GetScriptForDestination(const CTxDestination& dest)
  {
  - CScript script;
  -
  - boost::apply_visitor(CScriptVisitor(&script), dest);
  - return script;
  + return boost::apply_visitor(::g_script_visitor, dest);
  }
  CScript GetScriptForRawPubKey(const CPubKey& pubKey)
  