boost/system/detail/error_condition.hpp
#ifndef BOOST_SYSTEM_DETAIL_ERROR_CONDITION_HPP_INCLUDED
#define BOOST_SYSTEM_DETAIL_ERROR_CONDITION_HPP_INCLUDED
// Copyright Beman Dawes 2006, 2007
// Copyright Christoper Kohlhoff 2007
// Copyright Peter Dimov 2017-2021
//
// 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)
//
// See library home page at http://www.boost.org/libs/system
#include <boost/system/detail/error_category.hpp>
#include <boost/system/detail/generic_category.hpp>
#include <boost/system/detail/enable_if.hpp>
#include <boost/system/detail/is_same.hpp>
#include <boost/system/detail/errc.hpp>
#include <boost/system/detail/append_int.hpp>
#include <boost/system/is_error_condition_enum.hpp>
#include <boost/system/detail/config.hpp>
#include <boost/config.hpp>
namespace boost
{
namespace system
{
// class error_condition
// error_conditions are portable, error_codes are system or library specific
namespace detail
{
struct generic_value_tag
{
int value;
BOOST_SYSTEM_CONSTEXPR explicit generic_value_tag( int v ): value( v ) {}
};
} // namespace detail
class error_condition
{
private:
int val_;
error_category const * cat_;
private:
boost::ulong_long_type cat_id() const BOOST_NOEXCEPT
{
return cat_? cat_->id_: detail::generic_category_id;
}
public:
// constructors:
BOOST_SYSTEM_CONSTEXPR error_condition() BOOST_NOEXCEPT:
val_( 0 ), cat_( 0 )
{
}
BOOST_SYSTEM_CONSTEXPR error_condition( int val, const error_category & cat ) BOOST_NOEXCEPT:
val_( val ), cat_( &cat )
{
}
BOOST_SYSTEM_CONSTEXPR explicit error_condition( boost::system::detail::generic_value_tag vt ) BOOST_NOEXCEPT:
val_( vt.value ), cat_( 0 )
{
}
template<class ErrorConditionEnum> BOOST_SYSTEM_CONSTEXPR error_condition( ErrorConditionEnum e,
typename detail::enable_if<
is_error_condition_enum<ErrorConditionEnum>::value && !boost::system::detail::is_same<ErrorConditionEnum, errc::errc_t>::value
>::type* = 0) BOOST_NOEXCEPT
{
*this = make_error_condition( e );
}
template<class ErrorConditionEnum> BOOST_SYSTEM_CONSTEXPR error_condition( ErrorConditionEnum e,
typename detail::enable_if<boost::system::detail::is_same<ErrorConditionEnum, errc::errc_t>::value>::type* = 0) BOOST_NOEXCEPT:
val_( e ), cat_( 0 )
{
}
// modifiers:
BOOST_SYSTEM_CONSTEXPR void assign( int val, const error_category & cat ) BOOST_NOEXCEPT
{
val_ = val;
cat_ = &cat;
}
template<typename ErrorConditionEnum>
BOOST_SYSTEM_CONSTEXPR typename detail::enable_if<is_error_condition_enum<ErrorConditionEnum>::value, error_condition>::type &
operator=( ErrorConditionEnum val ) BOOST_NOEXCEPT
{
*this = error_condition( val );
return *this;
}
BOOST_SYSTEM_CONSTEXPR void clear() BOOST_NOEXCEPT
{
val_ = 0;
cat_ = 0;
}
// observers:
BOOST_SYSTEM_CONSTEXPR int value() const BOOST_NOEXCEPT
{
return val_;
}
BOOST_SYSTEM_CONSTEXPR const error_category & category() const BOOST_NOEXCEPT
{
return cat_? *cat_: generic_category();
}
std::string message() const
{
if( cat_ )
{
return cat_->message( value() );
}
else
{
return detail::generic_error_category_message( value() );
}
}
char const * message( char * buffer, std::size_t len ) const BOOST_NOEXCEPT
{
if( cat_ )
{
return cat_->message( value(), buffer, len );
}
else
{
return detail::generic_error_category_message( value(), buffer, len );
}
}
BOOST_SYSTEM_CONSTEXPR bool failed() const BOOST_NOEXCEPT
{
if( cat_ )
{
return detail::failed_impl( val_, *cat_ );
}
else
{
return val_ != 0;
}
}
#if !defined(BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS)
BOOST_SYSTEM_CONSTEXPR explicit operator bool() const BOOST_NOEXCEPT // true if error
{
return failed();
}
#else
typedef void (*unspecified_bool_type)();
static void unspecified_bool_true() {}
BOOST_SYSTEM_CONSTEXPR operator unspecified_bool_type() const BOOST_NOEXCEPT // true if error
{
return failed()? unspecified_bool_true: 0;
}
BOOST_SYSTEM_CONSTEXPR bool operator!() const BOOST_NOEXCEPT // true if no error
{
return !failed();
}
#endif
// relationals:
// the more symmetrical non-member syntax allows enum
// conversions work for both rhs and lhs.
BOOST_SYSTEM_CONSTEXPR inline friend bool operator==( const error_condition & lhs, const error_condition & rhs ) BOOST_NOEXCEPT
{
if( lhs.val_ != rhs.val_ )
{
return false;
}
else if( lhs.cat_ == 0 )
{
return rhs.cat_id() == detail::generic_category_id;
}
else if( rhs.cat_ == 0 )
{
return lhs.cat_id() == detail::generic_category_id;
}
else
{
return *lhs.cat_ == *rhs.cat_;
}
}
BOOST_SYSTEM_CONSTEXPR inline friend bool operator<( const error_condition & lhs, const error_condition & rhs ) BOOST_NOEXCEPT
{
error_category const& lcat = lhs.category();
error_category const& rcat = rhs.category();
return lcat < rcat || ( lcat == rcat && lhs.val_ < rhs.val_ );
}
BOOST_SYSTEM_CONSTEXPR inline friend bool operator!=( const error_condition & lhs, const error_condition & rhs ) BOOST_NOEXCEPT
{
return !( lhs == rhs );
}
#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
operator std::error_condition () const
{
// This condition must be the same as the one in error_category_impl.hpp
#if defined(BOOST_SYSTEM_AVOID_STD_GENERIC_CATEGORY)
return std::error_condition( value(), category() );
#else
if( cat_ )
{
return std::error_condition( val_, *cat_ );
}
else
{
return std::error_condition( val_, std::generic_category() );
}
#endif
}
inline friend bool operator==( std::error_code const & lhs, error_condition const & rhs ) BOOST_NOEXCEPT
{
return lhs == static_cast< std::error_condition >( rhs );
}
inline friend bool operator==( error_condition const & lhs, std::error_code const & rhs ) BOOST_NOEXCEPT
{
return static_cast< std::error_condition >( lhs ) == rhs;
}
inline friend bool operator!=( std::error_code const & lhs, error_condition const & rhs ) BOOST_NOEXCEPT
{
return !( lhs == rhs );
}
inline friend bool operator!=( error_condition const & lhs, std::error_code const & rhs ) BOOST_NOEXCEPT
{
return !( lhs == rhs );
}
#endif
std::string to_string() const
{
std::string r( "cond:" );
if( cat_ )
{
r += cat_->name();
}
else
{
r += "generic";
}
detail::append_int( r, value() );
return r;
}
template<class Ch, class Tr>
inline friend std::basic_ostream<Ch, Tr>&
operator<< (std::basic_ostream<Ch, Tr>& os, error_condition const & en)
{
os << en.to_string();
return os;
}
};
} // namespace system
} // namespace boost
#endif // #ifndef BOOST_SYSTEM_DETAIL_ERROR_CONDITION_HPP_INCLUDED