From a73db2a75cbe7c7f58744c43cc71275e7d5628e0 Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Tue, 6 Aug 2024 14:44:47 +1000
Subject: [PATCH] build: convert aligned_storage_t to memcpy for small types

aligend_storage_t is deprecated in clang-19 and no longer compiles
cleanly (generates a warning). These locations don't benefit from any
fancy schemes, so just memcpy to a local var and return.
---
 cruft/util/endian.hpp |  6 +++---
 cruft/util/view.hpp   | 10 +++++++---
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/cruft/util/endian.hpp b/cruft/util/endian.hpp
index e2de1f2b..b6de5abf 100644
--- a/cruft/util/endian.hpp
+++ b/cruft/util/endian.hpp
@@ -107,9 +107,9 @@ namespace cruft {
     >
     T readhe (u08 const *data)
     {
-        std::aligned_union_t <sizeof (T), T> buffer;
-        memcpy (reinterpret_cast<char *> (&buffer), data, sizeof (T));
-        return *reinterpret_cast<const T*> (&buffer);
+        T value;
+        memcpy (&value, data, sizeof (T));
+        return value;
     }
 
 
diff --git a/cruft/util/view.hpp b/cruft/util/view.hpp
index 62405622..3140ff75 100644
--- a/cruft/util/view.hpp
+++ b/cruft/util/view.hpp
@@ -931,10 +931,14 @@ namespace cruft {
         if (unlikely (sizeof (ValueT) > buffer.size () * sizeof (WordT)))
             throw std::runtime_error ("insufficient data for extraction");
 
-        std::aligned_storage_t<sizeof(ValueT),alignof(ValueT)> bytes;
-        memcpy (&bytes, buffer.data (), sizeof (ValueT));
+        WordT* const head = buffer.begin ();
         buffer = buffer.consume (sizeof (ValueT) / sizeof (WordT));
-        return *reinterpret_cast<ValueT const*> (&bytes);
+
+        // Don't use reinterpret_cast or other pointer schemes because it's quite easy to run into alignment issues.
+        // No one should really be using this for bulk reads anyway, so it shouldn't be a performance issue.
+        ValueT out;
+        memcpy (&out, head, sizeof (ValueT));
+        return out;
     }