From 40f205b3815212c7a0e4c204802c8566d322fd6c Mon Sep 17 00:00:00 2001
From: Mateusz Pusz <mateusz.pusz@gmail.com>
Date: Thu, 1 Oct 2020 13:39:36 +0200
Subject: [PATCH] fix: ambiguous case for empty list resolved

---
 src/include/units/bits/external/type_list.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/include/units/bits/external/type_list.h b/src/include/units/bits/external/type_list.h
index 53d71558..88ab7b1e 100644
--- a/src/include/units/bits/external/type_list.h
+++ b/src/include/units/bits/external/type_list.h
@@ -150,6 +150,11 @@ namespace detail {
 template<typename SortedList1, typename SortedList2, template<typename, typename> typename Pred>
 struct type_list_merge_sorted_impl;
 
+template<template<typename...> typename List, template<typename, typename> typename Pred>
+struct type_list_merge_sorted_impl<List<>, List<>, Pred> {
+  using type = List<>;
+};
+
 template<template<typename...> typename List, typename... Lhs, template<typename, typename> typename Pred>
 struct type_list_merge_sorted_impl<List<Lhs...>, List<>, Pred> {
   using type = List<Lhs...>;