Unordered: Reduce the amount of meta-stuff in the tests.

Some of this was there for older compilers, some is just premature
generalization. There's still too much metaprogramming, but these are things
that are relatively easy to remove.

[SVN r79356]

test/helpers/random_values.hpp

@@ -8,7 +8,7 @@
 
 #include "./list.hpp"
 #include <algorithm>
-#include <boost/mpl/if.hpp>
+#include <boost/detail/select_type.hpp>
 #include "./generators.hpp"
 #include "./metafunctions.hpp"
 
@@ -81,10 +81,12 @@ namespace test
 
     template <class X>
     struct unordered_generator_base
-        : public boost::mpl::if_<
-            test::is_set<X>,
+        : public boost::detail::if_true<
+            test::is_set<X>::value
+        >::BOOST_NESTED_TEMPLATE then<
             test::unordered_generator_set<X>,
-            test::unordered_generator_map<X> >
+            test::unordered_generator_map<X>
+        >
     {
     };