Bring in type-lisp from my scratch projects.

type_lisp.h

@@ -0,0 +1,92 @@
+static_assert( __cplusplus > 2020'00 );
+
+#pragma once
+
+#include <type_traits>
+
+namespace Alepha::inline Cavorite  ::detail::  type_lisp
+{
+	inline namespace exports {}
+
+	namespace exports
+	{
+		template< typename ... > struct TypeList {};
+
+		using Nil= TypeList<>;
+
+		template< typename T >
+		constexpr bool is_nil_v= std::is_same_v< T, Nil >;
+	}
+
+	template< typename T >
+	constexpr bool is_type_list_v= false;
+
+	template< typename ... Args >
+	constexpr bool is_type_list_v< TypeList< Args... > >{ true };
+
+	namespace exports
+	{
+		template< typename Type >
+		concept TypeListType= is_type_list_v< Type >:
+	}
+
+	template< typename T >
+	struct tuple_from_list;
+
+	namespace exports
+	{
+		template< typename List >
+		using tuple_from_list_t= typename tuple_from_list< List >::type;
+	}
+
+	template< typename ... Members >
+	struct tuple_from_list< TypeList< Members... > >
+	{
+		using type= std::tuple< Members... >;
+	};
+
+	template< typename List >
+	struct car_impl { using type= Nil; };
+
+	template< typename Arg0, typename ... Args >
+	struct car_impl< TypeList< Arg0, Args... > >
+	{
+		using type= Arg0;
+	};
+
+	template< typename List >
+	struct cdr_impl { using type= Nil; };
+
+	template< typename Arg0, typename ... Args >
+	struct cdr_impl< TypeList< Arg0, Args... > >
+	{
+		using type= TypeList< Args... >;
+	};
+
+	namespace exports
+	{
+		template< typename List >
+		using car_t= typename car_impl< List >::type;
+
+		template< typename List >
+		using cdr_t= typename cdr_impl< List >::type;
+	}
+
+	namespace exports
+	{
+		template< typename List, typename Element >
+		constexpr bool list_contains_v=
+			std::is_same_v< Element, car_t< List > >
+				or
+			list_contains_v< cdr_t< List >, Element >;
+
+		template< typename Element >
+		constexpr bool list_contains_v< Nil, Element >{};
+	}
+}
+
+namespace Alepha::Cavorite::inline exports::inline type_lisp
+{
+	using namespace detail::type_lisp::exports;
+}
+