1 files changed, 82 insertions, 0 deletions
diff --git a/boost/metaparse/v1/cpp11/impl/nth_of_c.hpp b/boost/metaparse/v1/cpp11/impl/nth_of_c.hpp
new file mode 100644
index 0000000000..771e6cd862
--- /dev/null
+++ b/boost/metaparse/v1/cpp11/impl/nth_of_c.hpp
@@ -0,0 +1,82 @@
+#ifndef BOOST_METAPARSE_V1_CPP11_IMPL_NTH_OF_C_HPP
+#define BOOST_METAPARSE_V1_CPP11_IMPL_NTH_OF_C_HPP
+
+// Copyright Abel Sinkovics (abel@sinkovics.hu)  2017.
+// 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/metaparse/v1/cpp11/impl/nth_of_c_skip_remaining.hpp>
+
+#include <boost/metaparse/v1/is_error.hpp>
+#include <boost/metaparse/v1/get_remaining.hpp>
+#include <boost/metaparse/v1/get_position.hpp>
+#include <boost/metaparse/v1/get_result.hpp>
+
+#include <type_traits>
+
+namespace boost
+{
+  namespace metaparse
+  {
+    namespace v1
+    {
+      namespace impl
+      {
+        template <int N, class S, class Pos, class... Ps>
+        struct nth_of_c;
+
+        template <int N, class S, class Pos, class P, class... Ps>
+        struct nth_of_c<N, S, Pos, P, Ps...>
+        {
+        private:
+          template <class NextResult>
+          struct apply_unchecked :
+            nth_of_c<
+              N - 1,
+              typename get_remaining<NextResult>::type,
+              typename get_position<NextResult>::type,
+              Ps...
+            >
+          {};
+
+        public:
+          typedef
+            typename std::conditional<
+              is_error<typename P::template apply<S, Pos>>::type::value,
+              typename P::template apply<S, Pos>,
+              apply_unchecked<typename P::template apply<S, Pos>>
+            >::type::type
+            type;
+        };
+
+        template <class P, class S, class Pos, class... Ps>
+        struct nth_of_c<0, S, Pos, P, Ps...>
+        {
+        private:
+          template <class NextResult>
+          struct apply_unchecked :
+            nth_of_c_skip_remaining<
+              typename get_result<NextResult>::type,
+              typename get_remaining<NextResult>::type,
+              typename get_position<NextResult>::type,
+              Ps...
+            >
+          {};
+
+        public:
+          typedef
+            typename std::conditional<
+              is_error<typename P::template apply<S, Pos>>::type::value,
+              typename P::template apply<S, Pos>,
+              apply_unchecked<typename P::template apply<S, Pos>>
+            >::type::type
+            type;
+        };
+      }
+    }
+  }
+}
+
+#endif
+