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- //
- // error_code.hpp
- // ~~~~~~~~~~~~~~
- //
- // Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
- //
- // Distributed under the Boost Software License, Version 1.0. (See accompanying
- // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
- //
-
- #ifndef ASIO_ERROR_CODE_HPP
- #define ASIO_ERROR_CODE_HPP
-
- #if defined(_MSC_VER) && (_MSC_VER >= 1200)
- # pragma once
- #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
-
- #include "asio/detail/config.hpp"
-
- #if defined(ASIO_HAS_STD_SYSTEM_ERROR)
- # include <system_error>
- #else // defined(ASIO_HAS_STD_SYSTEM_ERROR)
- # include <string>
- # include "asio/detail/noncopyable.hpp"
- # if !defined(ASIO_NO_IOSTREAM)
- # include <iosfwd>
- # endif // !defined(ASIO_NO_IOSTREAM)
- #endif // defined(ASIO_HAS_STD_SYSTEM_ERROR)
-
- #include "asio/detail/push_options.hpp"
-
- namespace asio {
-
- #if defined(ASIO_HAS_STD_SYSTEM_ERROR)
-
- typedef std::error_category error_category;
-
- #else // defined(ASIO_HAS_STD_SYSTEM_ERROR)
-
- /// Base class for all error categories.
- class error_category : private noncopyable
- {
- public:
- /// Destructor.
- virtual ~error_category()
- {
- }
-
- /// Returns a string naming the error gategory.
- virtual const char* name() const = 0;
-
- /// Returns a string describing the error denoted by @c value.
- virtual std::string message(int value) const = 0;
-
- /// Equality operator to compare two error categories.
- bool operator==(const error_category& rhs) const
- {
- return this == &rhs;
- }
-
- /// Inequality operator to compare two error categories.
- bool operator!=(const error_category& rhs) const
- {
- return !(*this == rhs);
- }
- };
-
- #endif // defined(ASIO_HAS_STD_SYSTEM_ERROR)
-
- /// Returns the error category used for the system errors produced by asio.
- extern ASIO_DECL const error_category& system_category();
-
- #if defined(ASIO_HAS_STD_SYSTEM_ERROR)
-
- typedef std::error_code error_code;
-
- #else // defined(ASIO_HAS_STD_SYSTEM_ERROR)
-
- /// Class to represent an error code value.
- class error_code
- {
- public:
- /// Default constructor.
- error_code()
- : value_(0),
- category_(&system_category())
- {
- }
-
- /// Construct with specific error code and category.
- error_code(int v, const error_category& c)
- : value_(v),
- category_(&c)
- {
- }
-
- /// Construct from an error code enum.
- template <typename ErrorEnum>
- error_code(ErrorEnum e)
- {
- *this = make_error_code(e);
- }
-
- /// Clear the error value to the default.
- void clear()
- {
- value_ = 0;
- category_ = &system_category();
- }
-
- /// Assign a new error value.
- void assign(int v, const error_category& c)
- {
- value_ = v;
- category_ = &c;
- }
-
- /// Get the error value.
- int value() const
- {
- return value_;
- }
-
- /// Get the error category.
- const error_category& category() const
- {
- return *category_;
- }
-
- /// Get the message associated with the error.
- std::string message() const
- {
- return category_->message(value_);
- }
-
- struct unspecified_bool_type_t
- {
- };
-
- typedef void (*unspecified_bool_type)(unspecified_bool_type_t);
-
- static void unspecified_bool_true(unspecified_bool_type_t) {}
-
- /// Operator returns non-null if there is a non-success error code.
- operator unspecified_bool_type() const
- {
- if (value_ == 0)
- return 0;
- else
- return &error_code::unspecified_bool_true;
- }
-
- /// Operator to test if the error represents success.
- bool operator!() const
- {
- return value_ == 0;
- }
-
- /// Equality operator to compare two error objects.
- friend bool operator==(const error_code& e1, const error_code& e2)
- {
- return e1.value_ == e2.value_ && e1.category_ == e2.category_;
- }
-
- /// Inequality operator to compare two error objects.
- friend bool operator!=(const error_code& e1, const error_code& e2)
- {
- return e1.value_ != e2.value_ || e1.category_ != e2.category_;
- }
-
- private:
- // The value associated with the error code.
- int value_;
-
- // The category associated with the error code.
- const error_category* category_;
- };
-
- # if !defined(ASIO_NO_IOSTREAM)
-
- /// Output an error code.
- template <typename Elem, typename Traits>
- std::basic_ostream<Elem, Traits>& operator<<(
- std::basic_ostream<Elem, Traits>& os, const error_code& ec)
- {
- os << ec.category().name() << ':' << ec.value();
- return os;
- }
-
- # endif // !defined(ASIO_NO_IOSTREAM)
-
- #endif // defined(ASIO_HAS_STD_SYSTEM_ERROR)
-
- } // namespace asio
-
- #include "asio/detail/pop_options.hpp"
-
- #if defined(ASIO_HEADER_ONLY)
- # include "asio/impl/error_code.ipp"
- #endif // defined(ASIO_HEADER_ONLY)
-
- #endif // ASIO_ERROR_CODE_HPP
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