Add tuple_for_each.

test/tuple_for_each_cx.cpp

@@ -0,0 +1,37 @@
+
+//  Copyright 2015 Peter Dimov.
+//
+// Distributed under the Boost Software License, Version 1.0.
+//
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/tuple_for_each.hpp>
+#include <boost/config.hpp>
+
+#if defined( BOOST_NO_CXX11_CONSTEXPR )
+
+int main() {}
+
+#else
+
+#include <tuple>
+#include <type_traits>
+
+struct assert_is_integral
+{
+    template<class T> constexpr bool operator()( T ) const
+    {
+        static_assert( std::is_integral<T>::value, "T must be an integral type" );
+        return true;
+    }
+};
+
+int main()
+{
+    constexpr std::tuple<int, short, char> tp{ 1, 2, 3 };
+    constexpr auto r = boost::tuple_for_each( tp, assert_is_integral() );
+    (void)r;
+}
+
+#endif