Add CScript::IsPayToTaproot()

Co-authored-by: Sebastian Falbesoner <sebastian.falbesoner@gmail.com>

Author: Sjors

src/script/script.cpp

@@ -238,6 +238,13 @@ bool CScript::IsPayToWitnessScriptHash() const
             (*this)[1] == 0x20);
 }
 
+bool CScript::IsPayToTaproot() const
+{
+    return (this->size() == 34 &&
+            (*this)[0] == OP_1 &&
+            (*this)[1] == 0x20);
+}
+
 // A witness program is any valid CScript that consists of a 1-byte push opcode
 // followed by a data push between 2 and 40 bytes.
 bool CScript::IsWitnessProgram(int& version, std::vector<unsigned char>& program) const

src/script/script.h

@@ -554,6 +554,8 @@ class CScript : public CScriptBase
 
     bool IsPayToScriptHash() const;
     bool IsPayToWitnessScriptHash() const;
+    // Extra-fast test for pay-to-taproot CScripts
+    bool IsPayToTaproot() const;
     bool IsWitnessProgram(int& version, std::vector<unsigned char>& program) const;
 
     /** Called by IsStandardTx and P2SH/BIP62 VerifyScript (which makes it consensus-critical). */