diff --git a/types.hpp b/types.hpp
index e9a42b29..5355eff7 100644
--- a/types.hpp
+++ b/types.hpp
@@ -17,17 +17,23 @@
  * Copyright 2011 Danny Robson <danny@nerdcruft.net>
  */
 
-#ifndef __TYPES_HPP
-#define __TYPES_HPP
+#ifndef __UTIL_TYPES_HPP
+#define __UTIL_TYPES_HPP
+
+#include "platform.hpp"
 
 #include <cstdint>
 #include <cstdlib>
 #include <memory>
 
 /// Returns the number of elements of a statically allocated array
+#if !defined(COMPILER_CLANG)
 template <typename T, size_t N>  
 size_t elems(T (&)[N])
     { return N; }
+#else
+#define elems(x) (sizeof(x) / 0[x])
+#endif
 
 
 template<class T, class...Args>
@@ -37,4 +43,4 @@ make_unique(Args&&... args) {
 }
 
 
-#endif // __TYPES_HPP
+#endif
diff --git a/types/casts.hpp b/types/casts.hpp
index fe408bd3..33f5ff24 100644
--- a/types/casts.hpp
+++ b/types/casts.hpp
@@ -41,13 +41,19 @@ namespace detail {
 
     template <typename T, typename V>
     T
-    _sign_cast (const typename std::enable_if<sizeof(T) == sizeof(V)   &&
+    _sign_cast (const typename std::enable_if<sizeof(T) == sizeof(V)  &&
                                              std::is_signed<T>::value &&
                                              std::is_unsigned<V>::value, V>::type v)
     {
         CHECK_HARD (v < std::numeric_limits<V>::max () / 2);
         return static_cast<T> (v);
     }
+
+
+    template <typename T, typename V>
+    T
+    _sign_cast (const typename std::enable_if<std::is_same<T, V>::value, V>::type v)
+        { return v; }
 }
 
 /// Safely cast a numeric type to its (un)signed counterpart, aborting if the