Add tuple_for_each.

include/boost/tuple_for_each.hpp

@@ -0,0 +1,33 @@
+#ifndef BOOST_TUPLE_FOR_EACH_HPP_INCLUDED
+#define BOOST_TUPLE_FOR_EACH_HPP_INCLUDED
+
+#include <boost/integer_sequence.hpp>
+#include <boost/config.hpp>
+#include <tuple>
+#include <utility>
+#include <type_traits>
+#include <cstddef>
+
+namespace boost
+{
+
+namespace detail
+{
+
+template<class Tp, std::size_t... J, class F> BOOST_CONSTEXPR F tuple_for_each_impl( Tp && tp, boost::integer_sequence<std::size_t, J...>, F && f )
+{
+    using A = int[sizeof...(J)];
+    return (void)A{ (f(std::get<J>(std::forward<Tp>(tp))), 0)... }, std::forward<F>(f);
+}
+
+} // namespace detail
+
+template<class Tp, class F> BOOST_CONSTEXPR F tuple_for_each( Tp && tp, F && f )
+{
+    using seq = boost::make_index_sequence<std::tuple_size<typename std::remove_reference<Tp>::type>::value>;
+    return detail::tuple_for_each_impl( std::forward<Tp>(tp), seq(), std::forward<F>(f) );
+}
+
+} // namespace boost
+
+#endif // #ifndef BOOST_TUPLE_FOR_EACH_HPP_INCLUDED