Merge bitcoin/bitcoin#23413: Replace MakeSpan helper with Span deduction guide

11daf6ceb1d9ea1f8d638b123eecfe39d162a7c3 More Span simplifications (Pieter Wuille)
568dd2f83900a11a4dbba1250722791a135bf0a9 Replace MakeSpan helper with Span deduction guide (Pieter Wuille)

Pull request description:

  C++17 supports [user-defined deduction guides](https://en.cppreference.com/w/cpp/language/class_template_argument_deduction), allowing class constructors to be invoked without specifying class template arguments. Instead, the code can contain rules to infer the template arguments from the constructor argument types.

  This alleviates the need for the `MakeSpan` helper. Convert the existing MakeSpan rules into deduction rules for `Span` itself, and replace all invocations of `MakeSpan` with just `Span` ones.

ACKs for top commit:
  MarcoFalke:
    re-ACK 11daf6ceb1d9ea1f8d638b123eecfe39d162a7c3 Only change is removing a hunk in the tests 🌕

Tree-SHA512: 10f3e82e4338f39d9b7b407cd11aac7ebe1e9191b58e3d7f4e5e338a4636c0e126b4a1d912127c7446f57ba356c8d6544482e47f97901efea6a54fffbfd7895f

1 files changed, 3 insertions, 3 deletions

diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
index d83ec7192b..6433ba1b58 100644
--- a/src/script/interpreter.cpp
+++ b/src/script/interpreter.cpp
@@ -1858,7 +1858,7 @@ uint256 ComputeTaprootMerkleRoot(Span<const unsigned char> control, const uint25
     uint256 k = tapleaf_hash;
     for (int i = 0; i < path_len; ++i) {
         CHashWriter ss_branch{HASHER_TAPBRANCH};
-        Span<const unsigned char> node(control.data() + TAPROOT_CONTROL_BASE_SIZE + TAPROOT_CONTROL_NODE_SIZE * i, TAPROOT_CONTROL_NODE_SIZE);
+        Span node{Span{control}.subspan(TAPROOT_CONTROL_BASE_SIZE + TAPROOT_CONTROL_NODE_SIZE * i, TAPROOT_CONTROL_NODE_SIZE)};
         if (std::lexicographical_compare(k.begin(), k.end(), node.begin(), node.end())) {
             ss_branch << k << node;
         } else {
@@ -1874,7 +1874,7 @@ static bool VerifyTaprootCommitment(const std::vector<unsigned char>& control, c
     assert(control.size() >= TAPROOT_CONTROL_BASE_SIZE);
     assert(program.size() >= uint256::size());
     //! The internal pubkey (x-only, so no Y coordinate parity).
-    const XOnlyPubKey p{Span<const unsigned char>{control.data() + 1, control.data() + TAPROOT_CONTROL_BASE_SIZE}};
+    const XOnlyPubKey p{Span{control}.subspan(1, TAPROOT_CONTROL_BASE_SIZE - 1)};
     //! The output pubkey (taken from the scriptPubKey).
     const XOnlyPubKey q{program};
     // Compute the Merkle root from the leaf and the provided path.
@@ -1886,7 +1886,7 @@ static bool VerifyTaprootCommitment(const std::vector<unsigned char>& control, c
 static bool VerifyWitnessProgram(const CScriptWitness& witness, int witversion, const std::vector<unsigned char>& program, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* serror, bool is_p2sh)
 {
     CScript exec_script; //!< Actually executed script (last stack item in P2WSH; implied P2PKH script in P2WPKH; leaf script in P2TR)
-    Span<const valtype> stack{witness.stack};
+    Span stack{witness.stack};
     ScriptExecutionData execdata;
 
     if (witversion == 0) {