1 // -*- C++ -*-
2 //===----------------------------------------------------------------------===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #ifndef _LIBCPP___SYSTEM_ERROR_ERROR_CONDITION_H
11 #define _LIBCPP___SYSTEM_ERROR_ERROR_CONDITION_H
12 
13 #include <__compare/ordering.h>
14 #include <__config>
15 #include <__functional/hash.h>
16 #include <__functional/unary_function.h>
17 #include <__system_error/errc.h>
18 #include <__system_error/error_category.h>
19 #include <cstddef>
20 #include <string>
21 
22 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23 #  pragma GCC system_header
24 #endif
25 
26 _LIBCPP_BEGIN_NAMESPACE_STD
27 
28 template <class _Tp>
29 struct _LIBCPP_TEMPLATE_VIS is_error_condition_enum : public false_type {};
30 
31 #if _LIBCPP_STD_VER >= 17
32 template <class _Tp>
33 inline constexpr bool is_error_condition_enum_v = is_error_condition_enum<_Tp>::value;
34 #endif
35 
36 template <>
37 struct _LIBCPP_TEMPLATE_VIS is_error_condition_enum<errc> : true_type {};
38 
39 #ifdef _LIBCPP_CXX03_LANG
40 template <>
41 struct _LIBCPP_TEMPLATE_VIS is_error_condition_enum<errc::__lx> : true_type {};
42 #endif
43 
44 namespace __adl_only {
45 // Those cause ADL to trigger but they are not viable candidates,
46 // so they are never actually selected.
47 void make_error_condition() = delete;
48 } // namespace __adl_only
49 
50 class _LIBCPP_EXPORTED_FROM_ABI error_condition {
51   int __val_;
52   const error_category* __cat_;
53 
54 public:
55   _LIBCPP_HIDE_FROM_ABI error_condition() _NOEXCEPT : __val_(0), __cat_(&generic_category()) {}
56 
57   _LIBCPP_HIDE_FROM_ABI error_condition(int __val, const error_category& __cat) _NOEXCEPT
58       : __val_(__val),
59         __cat_(&__cat) {}
60 
61   template <class _Ep>
62   _LIBCPP_HIDE_FROM_ABI
63   error_condition(_Ep __e, typename enable_if<is_error_condition_enum<_Ep>::value>::type* = nullptr) _NOEXCEPT {
64     using __adl_only::make_error_condition;
65     *this = make_error_condition(__e);
66   }
67 
68   _LIBCPP_HIDE_FROM_ABI void assign(int __val, const error_category& __cat) _NOEXCEPT {
69     __val_ = __val;
70     __cat_ = &__cat;
71   }
72 
73   template <class _Ep>
74   _LIBCPP_HIDE_FROM_ABI typename enable_if< is_error_condition_enum<_Ep>::value, error_condition& >::type
75   operator=(_Ep __e) _NOEXCEPT {
76     using __adl_only::make_error_condition;
77     *this = make_error_condition(__e);
78     return *this;
79   }
80 
81   _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT {
82     __val_ = 0;
83     __cat_ = &generic_category();
84   }
85 
86   _LIBCPP_HIDE_FROM_ABI int value() const _NOEXCEPT { return __val_; }
87 
88   _LIBCPP_HIDE_FROM_ABI const error_category& category() const _NOEXCEPT { return *__cat_; }
89   string message() const;
90 
91   _LIBCPP_HIDE_FROM_ABI explicit operator bool() const _NOEXCEPT { return __val_ != 0; }
92 };
93 
94 inline _LIBCPP_HIDE_FROM_ABI error_condition make_error_condition(errc __e) _NOEXCEPT {
95   return error_condition(static_cast<int>(__e), generic_category());
96 }
97 
98 inline _LIBCPP_HIDE_FROM_ABI bool operator==(const error_condition& __x, const error_condition& __y) _NOEXCEPT {
99   return __x.category() == __y.category() && __x.value() == __y.value();
100 }
101 
102 #if _LIBCPP_STD_VER <= 17
103 
104 inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const error_condition& __x, const error_condition& __y) _NOEXCEPT {
105   return !(__x == __y);
106 }
107 
108 inline _LIBCPP_HIDE_FROM_ABI bool operator<(const error_condition& __x, const error_condition& __y) _NOEXCEPT {
109   return __x.category() < __y.category() || (__x.category() == __y.category() && __x.value() < __y.value());
110 }
111 
112 #else // _LIBCPP_STD_VER <= 17
113 
114 inline _LIBCPP_HIDE_FROM_ABI strong_ordering
115 operator<=>(const error_condition& __x, const error_condition& __y) noexcept {
116   if (auto __c = __x.category() <=> __y.category(); __c != 0)
117     return __c;
118   return __x.value() <=> __y.value();
119 }
120 
121 #endif // _LIBCPP_STD_VER <= 17
122 
123 template <>
124 struct _LIBCPP_TEMPLATE_VIS hash<error_condition> : public __unary_function<error_condition, size_t> {
125   _LIBCPP_HIDE_FROM_ABI size_t operator()(const error_condition& __ec) const _NOEXCEPT {
126     return static_cast<size_t>(__ec.value());
127   }
128 };
129 
130 _LIBCPP_END_NAMESPACE_STD
131 
132 #endif // _LIBCPP___SYSTEM_ERROR_ERROR_CONDITION_H
133