From 60963a5d21b0560f79e7a88cf1af9b428c065dd3 Mon Sep 17 00:00:00 2001
From: John Maddock <john@johnmaddock.co.uk>
Date: Wed, 12 Sep 2007 16:44:16 +0000
Subject: [PATCH] Fixed is_base_of/is_base_and_derived so that you get a
 compiler error if you try and use them with an incomplete class type.

[SVN r39219]
---
 include/boost/type_traits/is_base_and_derived.hpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/boost/type_traits/is_base_and_derived.hpp b/include/boost/type_traits/is_base_and_derived.hpp
index a3157f7..23b9727 100644
--- a/include/boost/type_traits/is_base_and_derived.hpp
+++ b/include/boost/type_traits/is_base_and_derived.hpp
@@ -15,6 +15,7 @@
 #include <boost/type_traits/detail/ice_and.hpp>
 #include <boost/type_traits/remove_cv.hpp>
 #include <boost/config.hpp>
+#include <boost/static_assert.hpp>
 
 // should be the last #include
 #include <boost/type_traits/detail/bool_trait_def.hpp>
@@ -128,6 +129,13 @@ struct bd_helper
 template<typename B, typename D>
 struct is_base_and_derived_impl2
 {
+    //
+    // May silently do the wrong thing with incomplete types
+    // unless we trap them here:
+    //
+    BOOST_STATIC_ASSERT(sizeof(B));
+    BOOST_STATIC_ASSERT(sizeof(D));
+
     struct Host
     {
 #if !BOOST_WORKAROUND(BOOST_MSVC, == 1310)