#include <cstddef>
#include <iostream>
#include <boost/log/expressions.hpp>
#include <boost/log/sources/severity_channel_logger.hpp>
#include <boost/log/sources/record_ostream.hpp>
#include <boost/log/utility/setup/console.hpp>
#include <boost/log/utility/setup/common_attributes.hpp>
#include <boost/log/utility/setup/from_settings.hpp>
#include <boost/log/utility/setup/settings_parser.hpp>

namespace logging = boost::log;
namespace src = boost::log::sources;
namespace expr = boost::log::expressions;
namespace keywords = boost::log::keywords;

#if 1 // use normal enum
enum severity_level { normal, critical };
#else // simulate with typedef and #defs
typedef unsigned int severity_level;
#define normal 0
#define critical 1
#endif
std::ostream& operator<< (std::ostream& strm, severity_level level)
{
    std::cerr << __FILE__ << ":" << __LINE__ << ": operator<<(" << strm << ", " << static_cast< std::size_t >(level) << ")\n";
    static const char* strings[] = { "normal", "critical" };
    if (static_cast< std::size_t >(level) < 2)
        strm << strings[level];
    else
        strm << static_cast< int >(level);
    return strm;
}

BOOST_LOG_ATTRIBUTE_KEYWORD(line_id, "LineID", unsigned int)
BOOST_LOG_ATTRIBUTE_KEYWORD(severity, "Severity", severity_level)
BOOST_LOG_ATTRIBUTE_KEYWORD(channel, "Channel", std::string)

void init ()
{
    std::istringstream setstrm
	("[Sinks.TextFileSettings]\n" \
	 "Destination=Console\n"      \
	 "Format=\"parse: %LineID%: <%Severity%> [%Channel%] %Message%\"\n");
    logging::init_from_settings<char>(logging::parse_settings<char>(setstrm));

    logging::add_console_log(
        std::clog,
        keywords::format =
        (
            expr::stream
	        << "const: "
                << line_id
                << ": <" << severity
                << "> [" << channel << "] "
                << expr::smessage
        )
    );
}

int main (int, char*[])
{
    init();
    src::severity_channel_logger< severity_level, std::string > lg;
    BOOST_LOG_CHANNEL_SEV(lg, "channel 1", normal) << "normal channel 1";
    BOOST_LOG_CHANNEL_SEV(lg, "channel 2", critical) << "criticial channel 2";
    return 0;
}