libcxx/include/system_error

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_SYSTEM_ERROR
#define _LIBCPP_SYSTEM_ERROR

/*
    system_error synopsis

namespace std
{

class error_category
{
public:
    virtual ~error_category() noexcept;

    constexpr error_category();
    error_category(const error_category&) = delete;
    error_category& operator=(const error_category&) = delete;

    virtual const char* name() const noexcept = 0;
    virtual error_condition default_error_condition(int ev) const noexcept;
    virtual bool equivalent(int code, const error_condition& condition) const noexcept;
    virtual bool equivalent(const error_code& code, int condition) const noexcept;
    virtual string message(int ev) const = 0;

    bool operator==(const error_category& rhs) const noexcept;
    bool operator!=(const error_category& rhs) const noexcept;              // removed in C++20
    bool operator<(const error_category& rhs) const noexcept;               // removed in C++20
    strong_ordering operator<=>(const error_category& rhs) const noexcept;  // C++20
};

const error_category& generic_category() noexcept;
const error_category& system_category() noexcept;

template <class T> struct is_error_code_enum
    : public false_type {};

template <class T> struct is_error_condition_enum
    : public false_type {};

template <class _Tp>
inline constexpr bool is_error_condition_enum_v = is_error_condition_enum<_Tp>::value; // C++17

template <class _Tp>
inline constexpr bool is_error_code_enum_v = is_error_code_enum<_Tp>::value; // C++17

class error_code
{
public:
    // constructors:
    error_code() noexcept;
    error_code(int val, const error_category& cat) noexcept;
    template <class ErrorCodeEnum>
        error_code(ErrorCodeEnum e) noexcept;

    // modifiers:
    void assign(int val, const error_category& cat) noexcept;
    template <class ErrorCodeEnum>
        error_code& operator=(ErrorCodeEnum e) noexcept;
    void clear() noexcept;

    // observers:
    int value() const noexcept;
    const error_category& category() const noexcept;
    error_condition default_error_condition() const noexcept;
    string message() const;
    explicit operator bool() const noexcept;
};

// non-member functions:
template <class charT, class traits>
    basic_ostream<charT,traits>&
    operator<<(basic_ostream<charT,traits>& os, const error_code& ec);

class error_condition
{
public:
    // constructors:
    error_condition() noexcept;
    error_condition(int val, const error_category& cat) noexcept;
    template <class ErrorConditionEnum>
        error_condition(ErrorConditionEnum e) noexcept;

    // modifiers:
    void assign(int val, const error_category& cat) noexcept;
    template <class ErrorConditionEnum>
        error_condition& operator=(ErrorConditionEnum e) noexcept;
    void clear() noexcept;

    // observers:
    int value() const noexcept;
    const error_category& category() const noexcept;
    string message() const;
    explicit operator bool() const noexcept;
};

class system_error
    : public runtime_error
{
public:
    system_error(error_code ec, const string& what_arg);
    system_error(error_code ec, const char* what_arg);
    system_error(error_code ec);
    system_error(int ev, const error_category& ecat, const string& what_arg);
    system_error(int ev, const error_category& ecat, const char* what_arg);
    system_error(int ev, const error_category& ecat);

    const error_code& code() const noexcept;
    const char* what() const noexcept;
};

template <> struct is_error_condition_enum<errc>
    : true_type { }

error_code make_error_code(errc e) noexcept;
error_condition make_error_condition(errc e) noexcept;

// Comparison operators:
bool operator==(const error_code& lhs, const error_code& rhs) noexcept;
bool operator==(const error_code& lhs, const error_condition& rhs) noexcept;
bool operator==(const error_condition& lhs, const error_code& rhs) noexcept;                  // removed in C++20
bool operator==(const error_condition& lhs, const error_condition& rhs) noexcept;
bool operator!=(const error_code& lhs, const error_code& rhs) noexcept;                       // removed in C++20
bool operator!=(const error_code& lhs, const error_condition& rhs) noexcept;                  // removed in C++20
bool operator!=(const error_condition& lhs, const error_code& rhs) noexcept;                  // removed in C++20
bool operator!=(const error_condition& lhs, const error_condition& rhs) noexcept;             // removed in C++20
bool operator<(const error_condition& lhs, const error_condition& rhs) noexcept;              // removed in C++20
bool operator<(const error_code& lhs, const error_code& rhs) noexcept;                        // removed in C++20
strong_ordering operator<=>(const error_code& lhs, const error_code& rhs) noexcept;           // C++20
strong_ordering operator<=>(const error_condition& lhs, const error_condition& rhs) noexcept; // C++20

template <> struct hash<std::error_code>;
template <> struct hash<std::error_condition>;

}  // std

*/

#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
#  include <__cxx03/system_error>
#else
#  include <__config>
#  include <__system_error/errc.h>
#  include <__system_error/error_category.h>
#  include <__system_error/error_code.h>
#  include <__system_error/error_condition.h>
#  include <__system_error/system_error.h>
#  include <version>

// standard-mandated includes

// [system.error.syn]
#  include <compare>

#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#    pragma GCC system_header
#  endif

#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)

#endif // _LIBCPP_SYSTEM_ERROR