boost/system/detail/error_category.hpp
#ifndef BOOST_SYSTEM_DETAIL_ERROR_CATEGORY_HPP_INCLUDED
#define BOOST_SYSTEM_DETAIL_ERROR_CATEGORY_HPP_INCLUDED
// Copyright Beman Dawes 2006, 2007
// Copyright Christoper Kohlhoff 2007
// Copyright Peter Dimov 2017, 2018
//
// 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/config.hpp>
#include <boost/cstdint.hpp>
#include <boost/config.hpp>
#include <string>
#include <functional>
#include <cstddef>
#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
# include <system_error>
# include <atomic>
#endif
namespace boost
{
namespace system
{
class error_category;
class error_code;
class error_condition;
std::size_t hash_value( error_code const & ec );
namespace detail
{
BOOST_SYSTEM_CONSTEXPR bool failed_impl( int ev, error_category const & cat );
class std_category;
} // namespace detail
#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
#endif
#if defined(BOOST_MSVC) && BOOST_MSVC < 1900
#pragma warning(push)
#pragma warning(disable: 4351) // new behavior: elements of array will be default initialized
#endif
class BOOST_SYMBOL_VISIBLE error_category
{
private:
friend std::size_t hash_value( error_code const & ec );
friend BOOST_SYSTEM_CONSTEXPR bool detail::failed_impl( int ev, error_category const & cat );
friend class error_code;
friend class error_condition;
#if !defined(BOOST_NO_CXX11_DELETED_FUNCTIONS)
public:
error_category( error_category const & ) = delete;
error_category& operator=( error_category const & ) = delete;
#else
private:
error_category( error_category const & );
error_category& operator=( error_category const & );
#endif
private:
boost::ulong_long_type id_;
static std::size_t const stdcat_size_ = 4 * sizeof( void const* );
union
{
mutable unsigned char stdcat_[ stdcat_size_ ];
void const* stdcat_align_;
};
#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
mutable std::atomic< unsigned > sc_init_;
#else
unsigned sc_init_;
#endif
protected:
#if !defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS) && !defined(BOOST_NO_CXX11_NON_PUBLIC_DEFAULTED_FUNCTIONS)
~error_category() = default;
#else
// We'd like to make the destructor protected, to make code that deletes
// an error_category* not compile; unfortunately, doing the below makes
// the destructor user-provided and hence breaks use after main, as the
// categories may get destroyed before code that uses them
// ~error_category() {}
#endif
BOOST_SYSTEM_CONSTEXPR error_category() BOOST_NOEXCEPT: id_( 0 ), stdcat_(), sc_init_()
{
}
explicit BOOST_SYSTEM_CONSTEXPR error_category( boost::ulong_long_type id ) BOOST_NOEXCEPT: id_( id ), stdcat_(), sc_init_()
{
}
public:
virtual const char * name() const BOOST_NOEXCEPT = 0;
virtual error_condition default_error_condition( int ev ) const BOOST_NOEXCEPT;
virtual bool equivalent( int code, const error_condition & condition ) const BOOST_NOEXCEPT;
virtual bool equivalent( const error_code & code, int condition ) const BOOST_NOEXCEPT;
virtual std::string message( int ev ) const = 0;
virtual char const * message( int ev, char * buffer, std::size_t len ) const BOOST_NOEXCEPT;
virtual bool failed( int ev ) const BOOST_NOEXCEPT
{
return ev != 0;
}
friend BOOST_SYSTEM_CONSTEXPR bool operator==( error_category const & lhs, error_category const & rhs ) BOOST_NOEXCEPT
{
return rhs.id_ == 0? &lhs == &rhs: lhs.id_ == rhs.id_;
}
friend BOOST_SYSTEM_CONSTEXPR bool operator!=( error_category const & lhs, error_category const & rhs ) BOOST_NOEXCEPT
{
return !( lhs == rhs );
}
friend BOOST_SYSTEM_CONSTEXPR bool operator<( error_category const & lhs, error_category const & rhs ) BOOST_NOEXCEPT
{
if( lhs.id_ < rhs.id_ )
{
return true;
}
if( lhs.id_ > rhs.id_ )
{
return false;
}
if( rhs.id_ != 0 )
{
return false; // equal
}
return std::less<error_category const *>()( &lhs, &rhs );
}
#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
void init_stdcat() const;
# if defined(__SUNPRO_CC) // trailing __global is not supported
operator std::error_category const & () const;
# else
operator std::error_category const & () const BOOST_SYMBOL_VISIBLE;
# endif
#endif
};
#if defined(BOOST_MSVC) && BOOST_MSVC < 1900
#pragma warning(pop)
#endif
#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
#pragma GCC diagnostic pop
#endif
namespace detail
{
static const boost::ulong_long_type generic_category_id = ( boost::ulong_long_type( 0xB2AB117A ) << 32 ) + 0x257EDFD0;
static const boost::ulong_long_type system_category_id = generic_category_id + 1;
static const boost::ulong_long_type interop_category_id = generic_category_id + 2;
BOOST_SYSTEM_CONSTEXPR inline bool failed_impl( int ev, error_category const & cat )
{
if( cat.id_ == system_category_id || cat.id_ == generic_category_id )
{
return ev != 0;
}
else
{
return cat.failed( ev );
}
}
} // namespace detail
} // namespace system
} // namespace boost
#endif // #ifndef BOOST_SYSTEM_DETAIL_ERROR_CATEGORY_HPP_INCLUDED