zip_function: Add c++11 guard

Author: bjude

thrust/zip_function.h

@@ -1,5 +1,11 @@
 #pragma once
 
+#include <thrust/detail/config.h>
+#include <thrust/detail/cpp11_required.h>
+#include <thrust/detail/modern_gcc_required.h>
+
+#if THRUST_CPP_DIALECT >= 2011 && !defined(THRUST_LEGACY_GCC)
+
 #include <thrust/type_traits/integer_sequence.h>
 #include <thrust/detail/type_deduction.h>
 
@@ -53,4 +59,5 @@ auto make_zip_function(Function&& fun) -> zip_function<typename std::decay<Funct
     return zip_function<func_t>(THRUST_FWD(fun));
 }
 
-THRUST_END_NS
+
+#endif