Simplified `List`, `Length` and `Reverse` implementations

* continuation of 8e49cc6
* list constructor was generalized to a _variadic fold_

1 files changed, 34 insertions, 0 deletions

diff --git a/src/list/detail/fold_variadic.h b/src/list/detail/fold_variadic.h
new file mode 100644
index 0000000..e02b604
--- /dev/null
+++ b/src/list/detail/fold_variadic.h
@@ -0,0 +1,34 @@
+#ifndef TYPEASVALUE_SRC_LIST_DETAIL_FOLD_VARIADIC_H_
+#define TYPEASVALUE_SRC_LIST_DETAIL_FOLD_VARIADIC_H_
+
+#include "type.h"
+
+namespace tav {
+
+namespace detail {
+
+template <
+	template <typename, typename> class Function,
+	typename                            Head,
+	typename...                         Tail
+>
+struct fold_variadic {
+	typedef Function<
+		Head,
+		Eval<fold_variadic<Function, Tail...>>
+	> type;
+};
+
+template <
+	template <typename, typename> class Function,
+	typename                            Head
+>
+struct fold_variadic<Function, Head> {
+	typedef Function<Head, void> type;
+};
+
+}
+
+}
+
+#endif  // TYPEASVALUE_SRC_LIST_DETAIL_FOLD_VARIADIC_H_