用过滤器提升日志记录

Question

我是boost-log的新手,并尝试使用过滤器示例使用boost-log 1.1 进行简单的日志记录.代码如下所示:

#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";
}

使用clang进行编译会产生以下错误消息:

/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

看起来该示例基于较旧版本的boost-log,并且某些名称已更改.这个例子可以轻松修复吗？但是,似乎没有更新的教程.

Answer 1

文档中的示例似乎在包含之后缺少以下行:

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