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___TUPLE_TUPLE_SIZE_H
10 #define _LIBCPP___TUPLE_TUPLE_SIZE_H
11 
12 #include <__config>
13 #include <__fwd/tuple.h>
14 #include <__tuple/tuple_types.h>
15 #include <__type_traits/is_const.h>
16 #include <__type_traits/is_volatile.h>
17 #include <cstddef>
18 
19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20 #  pragma GCC system_header
21 #endif
22 
23 _LIBCPP_BEGIN_NAMESPACE_STD
24 
25 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_size;
26 
27 #if !defined(_LIBCPP_CXX03_LANG)
28 template <class _Tp, class...>
29 using __enable_if_tuple_size_imp = _Tp;
30 
31 template <class _Tp>
32 struct _LIBCPP_TEMPLATE_VIS tuple_size<__enable_if_tuple_size_imp<
33     const _Tp,
34     __enable_if_t<!is_volatile<_Tp>::value>,
35     integral_constant<size_t, sizeof(tuple_size<_Tp>)>>>
36     : public integral_constant<size_t, tuple_size<_Tp>::value> {};
37 
38 template <class _Tp>
39 struct _LIBCPP_TEMPLATE_VIS tuple_size<__enable_if_tuple_size_imp<
40     volatile _Tp,
41     __enable_if_t<!is_const<_Tp>::value>,
42     integral_constant<size_t, sizeof(tuple_size<_Tp>)>>>
43     : public integral_constant<size_t, tuple_size<_Tp>::value> {};
44 
45 template <class _Tp>
46 struct _LIBCPP_TEMPLATE_VIS tuple_size<__enable_if_tuple_size_imp<
47     const volatile _Tp,
48     integral_constant<size_t, sizeof(tuple_size<_Tp>)>>>
49     : public integral_constant<size_t, tuple_size<_Tp>::value> {};
50 
51 #else
52 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_size<const _Tp> : public tuple_size<_Tp> {};
53 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_size<volatile _Tp> : public tuple_size<_Tp> {};
54 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_size<const volatile _Tp> : public tuple_size<_Tp> {};
55 #endif
56 
57 #ifndef _LIBCPP_CXX03_LANG
58 
59 template <class ..._Tp>
60 struct _LIBCPP_TEMPLATE_VIS tuple_size<tuple<_Tp...> >
61     : public integral_constant<size_t, sizeof...(_Tp)>
62 {
63 };
64 
65 template <class ..._Tp>
66 struct _LIBCPP_TEMPLATE_VIS tuple_size<__tuple_types<_Tp...> >
67     : public integral_constant<size_t, sizeof...(_Tp)>
68 {
69 };
70 
71 #endif // _LIBCPP_CXX03_LANG
72 
73 _LIBCPP_END_NAMESPACE_STD
74 
75 #endif // _LIBCPP___TUPLE_TUPLE_SIZE_H
76