Question

Can anyone tell me what I’m doing wrong?

Running this on the console yields the following error:

# c++ -I /var/local/boost_1_46_1/ log.cpp -o log -lboost-log
log.cpp: In function âvoid init()â:
log.cpp:11: error: âboost::loggingâ has not been declared
log.cpp:13: error: âboost::fltâ has not been declared
log.cpp:13: error: âloggingâ has not been declared
log.cpp:13: error: âloggingâ has not been declared

I’ve also tried it explicitly linking the libraries from both stage and /usr/local/lib directories.

My log.cpp:

#include <boost/log/core.hpp>
#include <boost/log/trivial.hpp>
#include <boost/log/filters.hpp>

using namespace std;

void init()
{
    boost::logging::core::get()->set_filter
    (
        boost::flt::attr< boost::logging::trivial::severity_level >("Severity") >= boost::logging::trivial::info
    );

}

}

int main(int, char*[]) {
    BOOST_LOG_TRIVIAL(trace) << "A trace severity message";
    BOOST_LOG_TRIVIAL(debug) << "A debug severity message";
    BOOST_LOG_TRIVIAL(info) << "An informational severity message";
    BOOST_LOG_TRIVIAL(warning) << "A warning severity message";
    BOOST_LOG_TRIVIAL(error) << "An error severity message";
    BOOST_LOG_TRIVIAL(fatal) << "A fatal severity message";
}

This code will compile if I leave out the void init() function…

Answer 1

You need the following namespace redefinitions to use the tutorials:

namespace logging = boost::log;
namespace sinks = boost::log::sinks;
namespace src = boost::log::sources;
namespace fmt = boost::log::formatters;
namespace flt = boost::log::filters;
namespace attrs = boost::log::attributes;
namespace keywords = boost::log::keywords;

http://boost-log.sourceforge.net/libs/log/doc/html/log/how_to_read.html