Constrain the primary endian_reverse to not apply to class types; add test. Fixes #41.

include/boost/endian/conversion.hpp

@@ -46,7 +46,8 @@ namespace endian
   //  reverse byte order
   //  requires T to be a non-bool integral type
   //  in detail/endian_reverse.hpp
-  template<class T> inline BOOST_CONSTEXPR T endian_reverse( T x ) BOOST_NOEXCEPT;
+  //
+  //  template<class T> inline BOOST_CONSTEXPR T endian_reverse( T x ) BOOST_NOEXCEPT;
 
   //  reverse byte order unless native endianness is big
   template <class EndianReversible >
@@ -109,9 +110,11 @@ namespace endian
 
   //  reverse in place
   //  in detail/endian_reverse.hpp
-  template <class EndianReversible>
-    inline void endian_reverse_inplace(EndianReversible& x) BOOST_NOEXCEPT;
-    //  Effects: x = endian_reverse(x)
+  //
+  //  template <class EndianReversible>
+  //    inline void endian_reverse_inplace(EndianReversible& x) BOOST_NOEXCEPT;
+  //
+  //  Effects: x = endian_reverse(x)
 
   //  reverse in place unless native endianness is big
   template <class EndianReversibleInplace>

include/boost/endian/detail/endian_reverse.hpp

@@ -10,6 +10,8 @@
 #include <boost/endian/detail/intrinsic.hpp>
 #include <boost/type_traits/is_integral.hpp>
 #include <boost/type_traits/is_same.hpp>
+#include <boost/type_traits/enable_if.hpp>
+#include <boost/type_traits/is_class.hpp>
 #include <boost/static_assert.hpp>
 #include <boost/cstdint.hpp>
 #include <boost/config.hpp>
@@ -106,7 +108,9 @@ inline uint128_type BOOST_ENDIAN_CONSTEXPR endian_reverse_impl( uint128_type x )
 // Requires:
 //    T is non-bool integral
 
-template<class T> inline BOOST_CONSTEXPR T endian_reverse( T x ) BOOST_NOEXCEPT
+template<class T> inline BOOST_CONSTEXPR
+    typename enable_if_< !is_class<T>::value, T >::type
+    endian_reverse( T x ) BOOST_NOEXCEPT
 {
     BOOST_STATIC_ASSERT( is_integral<T>::value && !(is_same<T, bool>::value) );