From 9559a9506a2e293b1e4d61a7a93bd9532d2ff92a Mon Sep 17 00:00:00 2001
From: Pavel Kirienko <pavel.kirienko@gmail.com>
Date: Mon, 3 Feb 2014 14:41:27 +0400
Subject: [PATCH] Static assert for TX queue entry size

---
 .../include/uavcan/internal/static_assert.hpp | 30 +++++++++++++++++++
 .../uavcan/internal/transport/can_io.hpp      |  2 ++
 2 files changed, 32 insertions(+)
 create mode 100644 libuavcan/include/uavcan/internal/static_assert.hpp

diff --git a/libuavcan/include/uavcan/internal/static_assert.hpp b/libuavcan/include/uavcan/internal/static_assert.hpp
new file mode 100644
index 0000000000..85a707acf2
--- /dev/null
+++ b/libuavcan/include/uavcan/internal/static_assert.hpp
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2014 Pavel Kirienko <pavel.kirienko@gmail.com>
+ */
+
+#pragma once
+
+#include <cassert>
+
+namespace uavcan
+{
+
+/**
+ * Usage:
+ *  StaticAssert<expression>::check();
+ */
+template <bool VALUE>
+struct StaticAssert
+{
+#if __CDT_PARSER__
+    static void check() { assert(0); }
+#endif
+};
+
+template <>
+struct StaticAssert<true>
+{
+    static void check() { }
+};
+
+}
diff --git a/libuavcan/include/uavcan/internal/transport/can_io.hpp b/libuavcan/include/uavcan/internal/transport/can_io.hpp
index 98efa5431a..a0d6916a88 100644
--- a/libuavcan/include/uavcan/internal/transport/can_io.hpp
+++ b/libuavcan/include/uavcan/internal/transport/can_io.hpp
@@ -9,6 +9,7 @@
 #include <stdint.h>
 #include <uavcan/internal/linked_list.hpp>
 #include <uavcan/internal/dynamic_memory.hpp>
+#include <uavcan/internal/static_assert.hpp>
 #include <uavcan/can_driver.hpp>
 #include <uavcan/system_clock.hpp>
 
@@ -45,6 +46,7 @@ public:
         , qos(uint8_t(qos))
         {
             assert(qos == VOLATILE || qos == PERSISTENT);
+            StaticAssert<sizeof(Entry) <= 32>::check();
         }
 
         bool isExpired(uint64_t monotonic_timestamp) const { return monotonic_timestamp > monotonic_deadline; }