Unordered: Don't use SFINAE expression hack on Visual C++.

Sometimes it doesn't work. This means I can clean up the implementation
for other compilers, but I'll leave that for now.


[SVN r75167]

doc/compliance.qbk

@@ -36,9 +36,7 @@ A full implementation of `allocator_traits` requires sophisticated
 member function detection so that the fallback is used whenever the
 member function call is not well formed.
 This requires support for SFINAE expressions, which are available on
-GCC from version 4.4 and Clang. They aren't supported by
-Visual C++ 2008/2010, but with a bit of hacking it's possible to support
-certain use cases.
+GCC from version 4.4 and Clang.
 
 On other compilers, there's just a test to see if the allocator has
 a member, but no check that it can be called. So rather than using a

include/boost/unordered/detail/allocator_helpers.hpp

@@ -108,7 +108,7 @@ namespace boost { namespace unordered { namespace detail {
         convert_from_anything(T const&);
     };
 
-#if !defined(BOOST_NO_SFINAE_EXPR) || BOOST_WORKAROUND(BOOST_MSVC, >= 1500)
+#if !defined(BOOST_NO_SFINAE_EXPR)
 
 #   define BOOST_UNORDERED_HAVE_CALL_DETECTION 1