From 84eea5bb1ff2540639825d3b147dbd4655aa5152 Mon Sep 17 00:00:00 2001
From: rolandreichweinbmw <Roland.Reichwein@bmw.de>
Date: Sat, 14 Dec 2024 22:36:15 +0100
Subject: [PATCH] Packed unaligned_type (#989)

This way, unaligned_types like etl::be_uint32_t can be used in places where POD types are expected.
---
 include/etl/platform.h       | 8 ++++++++
 include/etl/unaligned_type.h | 2 +-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/include/etl/platform.h b/include/etl/platform.h
index e66a0e08..f8d8752d 100644
--- a/include/etl/platform.h
+++ b/include/etl/platform.h
@@ -454,6 +454,14 @@ SOFTWARE.
   #define ETL_HAS_INITIALIZER_LIST 0
 #endif
 
+//*************************************
+// Determine if the ETL should use __attribute__((packed).
+#if defined(ETL_COMPILER_CLANG) || defined(ETL_COMPILER_GCC) || defined(ETL_COMPILER_INTEL)
+  #define ETL_PACKED __attribute__((packed))
+#else
+  #define ETL_PACKED
+#endif
+
 //*************************************
 // Check for availability of certain builtins
 #include "profiles/determine_builtin_support.h"
diff --git a/include/etl/unaligned_type.h b/include/etl/unaligned_type.h
index 9b4ae662..77e38ce1 100644
--- a/include/etl/unaligned_type.h
+++ b/include/etl/unaligned_type.h
@@ -227,7 +227,7 @@ namespace etl
   ///\tparam Endian The endianness of the arithmetic type.
   //*************************************************************************
   template <typename T, int Endian_>
-  class unaligned_type : public private_unaligned_type::unaligned_type_common<sizeof(T)>
+  class ETL_PACKED unaligned_type : public private_unaligned_type::unaligned_type_common<sizeof(T)>
   {
   public: