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   typedef _Hp _Head;
24   typedef _Tp _Tail;
25 };
26 
27 template <class _TypeList, size_t _Size, bool = _Size <= sizeof(typename _TypeList::_Head)>
28 struct __find_first;
29 
30 template <class _Hp, class _Tp, size_t _Size>
31 struct __find_first<__type_list<_Hp, _Tp>, _Size, true> {
32   typedef _LIBCPP_NODEBUG _Hp type;
33 };
34 
35 template <class _Hp, class _Tp, size_t _Size>
36 struct __find_first<__type_list<_Hp, _Tp>, _Size, false> {
37   typedef _LIBCPP_NODEBUG typename __find_first<_Tp, _Size>::type type;
38 };
39 
40 _LIBCPP_END_NAMESPACE_STD
41 
42 #endif // _LIBCPP___TYPE_TRAITS_TYPE_LIST_H
43