1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef _LIBCPP___TYPE_TRAITS_TYPE_LIST_H
10 #define _LIBCPP___TYPE_TRAITS_TYPE_LIST_H
11 
12 #include <__config>
13 #include <cstddef>
14 
15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
16 #  pragma GCC system_header
17 #endif
18 
19 _LIBCPP_BEGIN_NAMESPACE_STD
20 
21 template <class _Hp, class _Tp>
22 struct __type_list
23 {
24     typedef _Hp _Head;
25     typedef _Tp _Tail;
26 };
27 
28 template <class _TypeList, size_t _Size, bool = _Size <= sizeof(typename _TypeList::_Head)> struct __find_first;
29 
30 template <class _Hp, class _Tp, size_t _Size>
31 struct __find_first<__type_list<_Hp, _Tp>, _Size, true>
32 {
33     typedef _LIBCPP_NODEBUG _Hp type;
34 };
35 
36 template <class _Hp, class _Tp, size_t _Size>
37 struct __find_first<__type_list<_Hp, _Tp>, _Size, false>
38 {
39     typedef _LIBCPP_NODEBUG typename __find_first<_Tp, _Size>::type type;
40 };
41 
42 _LIBCPP_END_NAMESPACE_STD
43 
44 #endif // _LIBCPP___TYPE_TRAITS_TYPE_LIST_H
45