Merge #20787: Use C++17 std::array deduction for OUTPUT_TYPES, ALL_FEE_ESTIMATE_HORIZONS

aaaa9878405f3f38f4f61c00feca110d7f9ca481 refactor: Use C++17 std::array deduction for ALL_FEE_ESTIMATE_HORIZONS (MarcoFalke)
fa39cdd072c91eac70cda04b8b26681611f94cb7 refactor: Use C++17 std::array deduction for OUTPUT_TYPES (MarcoFalke)

Pull request description:

  With the new C++17 array deduction rules, an array encompassing all values in an enum can be specified in the same header file that specifies the enum. This is useful to avoid having to repeatedly enumerate all enum values in the code. E.g. the RPC code, but also the fuzz code.

ACKs for top commit:
  theStack:
    cr ACK aaaa9878405f3f38f4f61c00feca110d7f9ca481 ⚙️
  fanquake:
    ACK aaaa9878405f3f38f4f61c00feca110d7f9ca481

Tree-SHA512: b71bd98f3ca07ddfec385735538ce89a4952e418b52dc990fb160187ccef1fc7ebc139d42988b6f7b48df24823af61f803b83d47fb7a3b82475f0c0b109bffb7

6 files changed, 19 insertions, 16 deletions

diff --git a/src/outputtype.cpp b/src/outputtype.cpp
index e978852826..d96fb282c5 100644
--- a/src/outputtype.cpp
+++ b/src/outputtype.cpp
@@ -19,8 +19,6 @@ static const std::string OUTPUT_TYPE_STRING_LEGACY = "legacy";
 static const std::string OUTPUT_TYPE_STRING_P2SH_SEGWIT = "p2sh-segwit";
 static const std::string OUTPUT_TYPE_STRING_BECH32 = "bech32";
 
-const std::array<OutputType, 3> OUTPUT_TYPES = {OutputType::LEGACY, OutputType::P2SH_SEGWIT, OutputType::BECH32};
-
 bool ParseOutputType(const std::string& type, OutputType& output_type)
 {
     if (type == OUTPUT_TYPE_STRING_LEGACY) {
diff --git a/src/outputtype.h b/src/outputtype.h
index 57316b92d6..88422e5824 100644
--- a/src/outputtype.h
+++ b/src/outputtype.h
@@ -20,7 +20,11 @@ enum class OutputType {
     BECH32,
 };
 
-extern const std::array<OutputType, 3> OUTPUT_TYPES;
+static constexpr auto OUTPUT_TYPES = std::array{
+    OutputType::LEGACY,
+    OutputType::P2SH_SEGWIT,
+    OutputType::BECH32,
+};
 
 [[nodiscard]] bool ParseOutputType(const std::string& str, OutputType& output_type);
 const std::string& FormatOutputType(OutputType type);
diff --git a/src/policy/fees.h b/src/policy/fees.h
index dd9f530c99..c444d71a31 100644
--- a/src/policy/fees.h
+++ b/src/policy/fees.h
@@ -11,6 +11,7 @@
 #include <random.h>
 #include <sync.h>
 
+#include <array>
 #include <map>
 #include <memory>
 #include <string>
@@ -25,9 +26,15 @@ class TxConfirmStats;
 /* Identifier for each of the 3 different TxConfirmStats which will track
  * history over different time horizons. */
 enum class FeeEstimateHorizon {
-    SHORT_HALFLIFE = 0,
-    MED_HALFLIFE = 1,
-    LONG_HALFLIFE = 2
+    SHORT_HALFLIFE,
+    MED_HALFLIFE,
+    LONG_HALFLIFE,
+};
+
+static constexpr auto ALL_FEE_ESTIMATE_HORIZONS = std::array{
+    FeeEstimateHorizon::SHORT_HALFLIFE,
+    FeeEstimateHorizon::MED_HALFLIFE,
+    FeeEstimateHorizon::LONG_HALFLIFE,
 };
 
 std::string StringForFeeEstimateHorizon(FeeEstimateHorizon horizon);
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 965b278bfa..52e033d0cc 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -1160,7 +1160,7 @@ static RPCHelpMan estimaterawfee()
 
     UniValue result(UniValue::VOBJ);
 
-    for (const FeeEstimateHorizon horizon : {FeeEstimateHorizon::SHORT_HALFLIFE, FeeEstimateHorizon::MED_HALFLIFE, FeeEstimateHorizon::LONG_HALFLIFE}) {
+    for (const FeeEstimateHorizon horizon : ALL_FEE_ESTIMATE_HORIZONS) {
         CFeeRate feeRate;
         EstimationResult buckets;
 
diff --git a/src/test/fuzz/kitchen_sink.cpp b/src/test/fuzz/kitchen_sink.cpp
index 4dfb2e3da0..fa4024fc38 100644
--- a/src/test/fuzz/kitchen_sink.cpp
+++ b/src/test/fuzz/kitchen_sink.cpp
@@ -28,12 +28,6 @@ constexpr TransactionError ALL_TRANSACTION_ERROR[] = {
     TransactionError::SIGHASH_MISMATCH,
     TransactionError::MAX_FEE_EXCEEDED,
 };
-
-constexpr FeeEstimateHorizon ALL_FEE_EST_HORIZON[] = {
-    FeeEstimateHorizon::SHORT_HALFLIFE,
-    FeeEstimateHorizon::MED_HALFLIFE,
-    FeeEstimateHorizon::LONG_HALFLIFE,
-};
 }; // namespace
 
 // The fuzzing kitchen sink: Fuzzing harness for functions that need to be
@@ -48,7 +42,7 @@ FUZZ_TARGET(kitchen_sink)
     (void)RPCErrorFromTransactionError(transaction_error);
     (void)TransactionErrorString(transaction_error);
 
-    (void)StringForFeeEstimateHorizon(fuzzed_data_provider.PickValueInArray(ALL_FEE_EST_HORIZON));
+    (void)StringForFeeEstimateHorizon(fuzzed_data_provider.PickValueInArray(ALL_FEE_ESTIMATE_HORIZONS));
 
     const OutputType output_type = fuzzed_data_provider.PickValueInArray(OUTPUT_TYPES);
     const std::string& output_type_string = FormatOutputType(output_type);
diff --git a/src/test/fuzz/policy_estimator.cpp b/src/test/fuzz/policy_estimator.cpp
index 8a17a4b51b..35cfc5230b 100644
--- a/src/test/fuzz/policy_estimator.cpp
+++ b/src/test/fuzz/policy_estimator.cpp
@@ -66,10 +66,10 @@ FUZZ_TARGET_INIT(policy_estimator, initialize_policy_estimator)
         }
         (void)block_policy_estimator.estimateFee(fuzzed_data_provider.ConsumeIntegral<int>());
         EstimationResult result;
-        (void)block_policy_estimator.estimateRawFee(fuzzed_data_provider.ConsumeIntegral<int>(), fuzzed_data_provider.ConsumeFloatingPoint<double>(), fuzzed_data_provider.PickValueInArray({FeeEstimateHorizon::SHORT_HALFLIFE, FeeEstimateHorizon::MED_HALFLIFE, FeeEstimateHorizon::LONG_HALFLIFE}), fuzzed_data_provider.ConsumeBool() ? &result : nullptr);
+        (void)block_policy_estimator.estimateRawFee(fuzzed_data_provider.ConsumeIntegral<int>(), fuzzed_data_provider.ConsumeFloatingPoint<double>(), fuzzed_data_provider.PickValueInArray(ALL_FEE_ESTIMATE_HORIZONS), fuzzed_data_provider.ConsumeBool() ? &result : nullptr);
         FeeCalculation fee_calculation;
         (void)block_policy_estimator.estimateSmartFee(fuzzed_data_provider.ConsumeIntegral<int>(), fuzzed_data_provider.ConsumeBool() ? &fee_calculation : nullptr, fuzzed_data_provider.ConsumeBool());
-        (void)block_policy_estimator.HighestTargetTracked(fuzzed_data_provider.PickValueInArray({FeeEstimateHorizon::SHORT_HALFLIFE, FeeEstimateHorizon::MED_HALFLIFE, FeeEstimateHorizon::LONG_HALFLIFE}));
+        (void)block_policy_estimator.HighestTargetTracked(fuzzed_data_provider.PickValueInArray(ALL_FEE_ESTIMATE_HORIZONS));
     }
     {
         FuzzedAutoFileProvider fuzzed_auto_file_provider = ConsumeAutoFile(fuzzed_data_provider);