Add integer_sequence.hpp.

include/boost/integer_sequence.hpp

@@ -0,0 +1,85 @@
+#ifndef BOOST_INTEGER_SEQUENCE_HPP_INCLUDED
+#define BOOST_INTEGER_SEQUENCE_HPP_INCLUDED
+
+#include <cstddef>
+
+namespace boost
+{
+
+// integer_sequence
+template<class T, T... I> struct integer_sequence
+{
+};
+
+// detail::make_integer_sequence_impl
+namespace detail
+{
+
+// iseq_if_c
+template<bool C, class T, class E> struct iseq_if_c_impl;
+
+template<class T, class E> struct iseq_if_c_impl<true, T, E>
+{
+    using type = T;
+};
+
+template<class T, class E> struct iseq_if_c_impl<false, T, E>
+{
+    using type = E;
+};
+
+template<bool C, class T, class E> using iseq_if_c = typename iseq_if_c_impl<C, T, E>::type;
+
+// iseq_identity
+template<class T> struct iseq_identity
+{
+    using type = T;
+};
+
+template<class S1, class S2> struct append_integer_sequence;
+
+template<class T, T... I, T... J> struct append_integer_sequence<integer_sequence<T, I...>, integer_sequence<T, J...>>
+{
+    using type = integer_sequence< T, I..., ( J + sizeof...(I) )... >;
+};
+
+template<class T, T N> struct make_integer_sequence_impl;
+
+template<class T, T N> struct make_integer_sequence_impl_
+{
+private:
+
+    static T const M = N / 2;
+    static T const R = N % 2;
+
+    using S1 = typename make_integer_sequence_impl<T, M>::type;
+    using S2 = typename append_integer_sequence<S1, S1>::type;
+    using S3 = typename make_integer_sequence_impl<T, R>::type;
+    using S4 = typename append_integer_sequence<S2, S3>::type;
+
+public:
+
+    using type = S4;
+};
+
+template<class T, T N> struct make_integer_sequence_impl: iseq_if_c<N == 0, iseq_identity<integer_sequence<T>>, iseq_if_c<N == 1, iseq_identity<integer_sequence<T, 0>>, make_integer_sequence_impl_<T, N>>>
+{
+};
+
+} // namespace detail
+
+// make_integer_sequence
+template<class T, T N> using make_integer_sequence = typename detail::make_integer_sequence_impl<T, N>::type;
+
+// index_sequence
+template<std::size_t... I> using index_sequence = integer_sequence<std::size_t, I...>;
+
+// make_index_sequence
+template<std::size_t N> using make_index_sequence = make_integer_sequence<std::size_t, N>;
+
+// index_sequence_for
+template<class... T> using index_sequence_for = make_integer_sequence<std::size_t, sizeof...(T)>;
+
+} // namespace boost
+
+#endif // #ifndef BOOST_INTEGER_SEQUENCE_HPP_INCLUDED

test/Jamfile.v2

@@ -43,3 +43,6 @@ run mp_identity.cpp : : : $(REQ) ;
 run mp_inherit.cpp : : : $(REQ) ;
 run mp_if.cpp : : : $(REQ) ;
 run mp_eval_if.cpp : : : $(REQ) ;
+
+# integer_sequence
+run integer_sequence.cpp : : : $(REQ) ;

test/integer_sequence.cpp

@@ -0,0 +1,53 @@
+
+//  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/integer_sequence.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+#include <type_traits>
+
+int main()
+{
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<int, 0>, boost::integer_sequence<int>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<int, 1>, boost::integer_sequence<int, 0>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<int, 2>, boost::integer_sequence<int, 0, 1>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<int, 3>, boost::integer_sequence<int, 0, 1, 2>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<int, 4>, boost::integer_sequence<int, 0, 1, 2, 3>>));
+
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<char, 0>, boost::integer_sequence<char>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<char, 1>, boost::integer_sequence<char, 0>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<char, 2>, boost::integer_sequence<char, 0, 1>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<char, 3>, boost::integer_sequence<char, 0, 1, 2>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<char, 4>, boost::integer_sequence<char, 0, 1, 2, 3>>));
+
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<std::size_t, 0>, boost::integer_sequence<std::size_t>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<std::size_t, 1>, boost::integer_sequence<std::size_t, 0>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<std::size_t, 2>, boost::integer_sequence<std::size_t, 0, 1>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<std::size_t, 3>, boost::integer_sequence<std::size_t, 0, 1, 2>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_integer_sequence<std::size_t, 4>, boost::integer_sequence<std::size_t, 0, 1, 2, 3>>));
+
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_index_sequence<0>, boost::integer_sequence<std::size_t>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_index_sequence<1>, boost::integer_sequence<std::size_t, 0>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_index_sequence<2>, boost::integer_sequence<std::size_t, 0, 1>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_index_sequence<3>, boost::integer_sequence<std::size_t, 0, 1, 2>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_index_sequence<4>, boost::integer_sequence<std::size_t, 0, 1, 2, 3>>));
+
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_index_sequence<0>, boost::index_sequence<>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_index_sequence<1>, boost::index_sequence<0>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_index_sequence<2>, boost::index_sequence<0, 1>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_index_sequence<3>, boost::index_sequence<0, 1, 2>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::make_index_sequence<4>, boost::index_sequence<0, 1, 2, 3>>));
+
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::index_sequence_for<>, boost::index_sequence<>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::index_sequence_for<void>, boost::index_sequence<0>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::index_sequence_for<void, void>, boost::index_sequence<0, 1>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::index_sequence_for<void, void, void>, boost::index_sequence<0, 1, 2>>));
+    BOOST_TEST_TRAIT_TRUE((std::is_same<boost::index_sequence_for<void, void, void, void>, boost::index_sequence<0, 1, 2, 3>>));
+
+    return boost::report_errors();
+}