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 <string>
 20
 21#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 22#  pragma GCC system_header
 23#endif
 24
 25_LIBCPP_BEGIN_NAMESPACE_STD
 26
 27template <class _Tp>
 28struct is_error_condition_enum : public false_type {};
 29
 30#if _LIBCPP_STD_VER >= 17
 31template <class _Tp>
 32inline constexpr bool is_error_condition_enum_v = is_error_condition_enum<_Tp>::value;
 33#endif
 34
 35template <>
 36struct is_error_condition_enum<errc> : true_type {};
 37
 38#ifdef _LIBCPP_CXX03_LANG
 39template <>
 40struct is_error_condition_enum<errc::__lx> : true_type {};
 41#endif
 42
 43namespace __adl_only {
 44// Those cause ADL to trigger but they are not viable candidates,
 45// so they are never actually selected.
 46void make_error_condition() = delete;
 47} // namespace __adl_only
 48
 49class _LIBCPP_EXPORTED_FROM_ABI error_condition {
 50  int __val_;
 51  const error_category* __cat_;
 52
 53public:
 54  _LIBCPP_HIDE_FROM_ABI error_condition() _NOEXCEPT : __val_(0), __cat_(&generic_category()) {}
 55
 56  _LIBCPP_HIDE_FROM_ABI error_condition(int __val, const error_category& __cat) _NOEXCEPT
 57      : __val_(__val),
 58        __cat_(&__cat) {}
 59
 60  template <class _Ep, __enable_if_t<is_error_condition_enum<_Ep>::value, int> = 0>
 61  _LIBCPP_HIDE_FROM_ABI error_condition(_Ep __e) _NOEXCEPT {
 62    using __adl_only::make_error_condition;
 63    *this = make_error_condition(__e);
 64  }
 65
 66  _LIBCPP_HIDE_FROM_ABI void assign(int __val, const error_category& __cat) _NOEXCEPT {
 67    __val_ = __val;
 68    __cat_ = &__cat;
 69  }
 70
 71  template <class _Ep, __enable_if_t<is_error_condition_enum<_Ep>::value, int> = 0>
 72  _LIBCPP_HIDE_FROM_ABI error_condition& operator=(_Ep __e) _NOEXCEPT {
 73    using __adl_only::make_error_condition;
 74    *this = make_error_condition(__e);
 75    return *this;
 76  }
 77
 78  _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT {
 79    __val_ = 0;
 80    __cat_ = &generic_category();
 81  }
 82
 83  _LIBCPP_HIDE_FROM_ABI int value() const _NOEXCEPT { return __val_; }
 84
 85  _LIBCPP_HIDE_FROM_ABI const error_category& category() const _NOEXCEPT { return *__cat_; }
 86  string message() const;
 87
 88  _LIBCPP_HIDE_FROM_ABI explicit operator bool() const _NOEXCEPT { return __val_ != 0; }
 89};
 90
 91inline _LIBCPP_HIDE_FROM_ABI error_condition make_error_condition(errc __e) _NOEXCEPT {
 92  return error_condition(static_cast<int>(__e), generic_category());
 93}
 94
 95inline _LIBCPP_HIDE_FROM_ABI bool operator==(const error_condition& __x, const error_condition& __y) _NOEXCEPT {
 96  return __x.category() == __y.category() && __x.value() == __y.value();
 97}
 98
 99#if _LIBCPP_STD_VER <= 17
100
101inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const error_condition& __x, const error_condition& __y) _NOEXCEPT {
102  return !(__x == __y);
103}
104
105inline _LIBCPP_HIDE_FROM_ABI bool operator<(const error_condition& __x, const error_condition& __y) _NOEXCEPT {
106  return __x.category() < __y.category() || (__x.category() == __y.category() && __x.value() < __y.value());
107}
108
109#else // _LIBCPP_STD_VER <= 17
110
111inline _LIBCPP_HIDE_FROM_ABI strong_ordering
112operator<=>(const error_condition& __x, const error_condition& __y) noexcept {
113  if (auto __c = __x.category() <=> __y.category(); __c != 0)
114    return __c;
115  return __x.value() <=> __y.value();
116}
117
118#endif // _LIBCPP_STD_VER <= 17
119
120template <>
121struct hash<error_condition> : public __unary_function<error_condition, size_t> {
122  _LIBCPP_HIDE_FROM_ABI size_t operator()(const error_condition& __ec) const _NOEXCEPT {
123    return static_cast<size_t>(__ec.value());
124  }
125};
126
127_LIBCPP_END_NAMESPACE_STD
128
129#endif // _LIBCPP___SYSTEM_ERROR_ERROR_CONDITION_H