boost logging with filters

Question

I am new to boost-log and tried to make the trivial logging with filters example work with boost-log 1.1. The code looks like this:

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

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

int main(int, char*[])
{
    BOOST_LOG_TRIVIAL(trace) << "A trace severity message";
}

Compiling this with clang results the following error messages:

/Users/admin/Documents/cmake tests/boost-log/main.cpp:7:5: error: use of undeclared identifier 'logging'
    logging::core::get()->set_filter
    ^
/Users/admin/Documents/cmake tests/boost-log/main.cpp:9:3: error: use of undeclared identifier 'filters'; did you mean 'boost::log_mt_posix::filters'?
         filters::attr< logging::trivial::severity_level >("Severity") >= logging::trivial::info
         ^~~~~~~
         boost::log_mt_posix::filters
/usr/local/include/boost/log/filters/has_attr.hpp:32:11: note: 'boost::log_mt_posix::filters' declared here
namespace filters {
          ^
/Users/admin/Documents/cmake tests/boost-log/main.cpp:9:18: error: use of undeclared identifier 'logging'
         filters::attr< logging::trivial::severity_level >("Severity") >= logging::trivial::info

It looks like the example is based on an older version of boost-log and some names have changed. Can the example be easily fixed? An updated tutorial however does not seem to be available.

Answer 1

The example in the docs just seems to be missing the following lines after the includes:

namespace logging = boost::log;
namespace filters = boost::log::filters;