Add DISABLE_VARIADIC_VECTOR and SFINAE for c++11 tuple element construction

include/boost/fusion/tuple/tuple.hpp

@@ -20,12 +20,15 @@
 ///////////////////////////////////////////////////////////////////////////////
 // C++11 interface
 ///////////////////////////////////////////////////////////////////////////////
+#include <boost/core/enable_if.hpp>
 #include <boost/fusion/container/vector/vector.hpp>
 #include <boost/fusion/sequence/intrinsic/size.hpp>
 #include <boost/fusion/sequence/intrinsic/value_at.hpp>
 #include <boost/fusion/sequence/intrinsic/at.hpp>
 #include <boost/fusion/sequence/comparison.hpp>
 #include <boost/fusion/sequence/io.hpp>
+#include <boost/fusion/support/detail/and.hpp>
+#include <boost/type_traits/is_convertible.hpp>
 #include <utility>
 
 namespace boost { namespace fusion
@@ -49,13 +52,29 @@ namespace boost { namespace fusion
         tuple(tuple<U...>&& other)
             : base_type(std::move(other)) {}
 
-        template <typename ...U>
+        template <
+            typename ...U
+          , typename = typename boost::enable_if_c<(
+                fusion::detail::and_<is_convertible<U, T>...>::value && 
+                sizeof...(U) >= 1
+            )>::type
+        >
         /*BOOST_CONSTEXPR*/ BOOST_FUSION_GPU_ENABLED
         explicit
         tuple(U&&... args)
             : base_type(std::forward<U>(args)...) {}
 
-        template <typename U>
+        template<typename U1, typename U2>
+        BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
+        tuple(std::pair<U1, U2> const& other)
+            : base_type(other.first, other.second) {}
+
+        template<typename U1, typename U2>
+        BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
+        tuple(std::pair<U1, U2>&& other)
+            : base_type(std::move(other.first), std::move(other.second)) {}
+
+        template<typename U>
         BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
         tuple& operator=(U&& rhs)
         {

include/boost/fusion/tuple/tuple_fwd.hpp

@@ -12,6 +12,7 @@
 #include <boost/fusion/container/vector/detail/config.hpp>
 
 #if  !defined(BOOST_FUSION_HAS_VARIADIC_VECTOR) \
+  || defined(BOOST_NO_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGS) \
   || (defined(__WAVE__) && defined(BOOST_FUSION_CREATE_PREPROCESSED_FILES))
 # if defined(BOOST_FUSION_HAS_VARIADIC_TUPLE)
 #   undef BOOST_FUSION_HAS_VARIADIC_TUPLE