3 files changed, 32 insertions, 3 deletions
diff --git a/src/util/message.cpp b/src/util/message.cpp
index ec845aeffb..1afb28cc10 100644
--- a/src/util/message.cpp
+++ b/src/util/message.cpp
@@ -47,7 +47,7 @@ MessageVerificationResult MessageVerify(
         return MessageVerificationResult::ERR_PUBKEY_NOT_RECOVERED;
     }
 
-    if (!(CTxDestination(PKHash(pubkey)) == destination)) {
+    if (!(PKHash(pubkey) == *std::get_if<PKHash>(&destination))) {
         return MessageVerificationResult::ERR_NOT_SIGNED;
     }
 
diff --git a/src/util/time.h b/src/util/time.h
index b6aab615ba..6aa776137c 100644
--- a/src/util/time.h
+++ b/src/util/time.h
@@ -6,8 +6,6 @@
 #ifndef BITCOIN_UTIL_TIME_H
 #define BITCOIN_UTIL_TIME_H
 
-#include <compat/compat.h>
-
 #include <chrono> // IWYU pragma: export
 #include <cstdint>
 #include <string>
diff --git a/src/util/vector.h b/src/util/vector.h
index 9b9218e54f..1513562f1b 100644
--- a/src/util/vector.h
+++ b/src/util/vector.h
@@ -5,7 +5,9 @@
 #ifndef BITCOIN_UTIL_VECTOR_H
 #define BITCOIN_UTIL_VECTOR_H
 
+#include <functional>
 #include <initializer_list>
+#include <optional>
 #include <type_traits>
 #include <utility>
 #include <vector>
@@ -49,4 +51,33 @@ inline V Cat(V v1, const V& v2)
     return v1;
 }
 
+/** Clear a vector (or std::deque) and release its allocated memory. */
+template<typename V>
+inline void ClearShrink(V& v) noexcept
+{
+    // There are various ways to clear a vector and release its memory:
+    //
+    // 1. V{}.swap(v)
+    // 2. v = V{}
+    // 3. v = {}; v.shrink_to_fit();
+    // 4. v.clear(); v.shrink_to_fit();
+    //
+    // (2) does not appear to release memory in glibc debug mode, even if v.shrink_to_fit()
+    // follows. (3) and (4) rely on std::vector::shrink_to_fit, which is only a non-binding
+    // request. Therefore, we use method (1).
+
+    V{}.swap(v);
+}
+
+template<typename V, typename L>
+inline std::optional<V> FindFirst(const std::vector<V>& vec, const L fnc)
+{
+    for (const auto& el : vec) {
+        if (fnc(el)) {
+            return el;
+        }
+    }
+    return std::nullopt;
+}
+
 #endif // BITCOIN_UTIL_VECTOR_H