我使用的是 Boost-Log 2.0，它与版本 1 有一些不同，我很难输出“严重性”属性。

我正在使用“Boost.Format-style”格式化程序

"%TimeStamp% [%Uptime%] (%LineID%) <%Severity%>: %Message%"

TimeStamp , LineID , 和 Message是 common_attributes . Uptime是我使用 attrs::timer() 添加的属性.我以为 Severity使用 severity_logger 时自动添加，但显然不是，这是我的问题。我得到空的严重性，例如:

2013-Apr-06 19:21:52.408974 [00:00:00.001337] (3) <>: A warning severity message

注意空的 <> .我尝试使用 register_simple_formatter_factory 添加严重性但后来我得到编译器错误:

error: no matching function for call to ‘register_simple_formatter_factory(const char [9])’

我不明白为什么。

这是我的代码:

#include <iostream>


#include <boost/log/common.hpp>
#include <boost/log/core.hpp>
#include <boost/log/trivial.hpp>
#include <boost/log/expressions.hpp>
#include <boost/log/sinks/text_file_backend.hpp>
#include <boost/log/sinks/sync_frontend.hpp>
#include <boost/log/sinks/text_ostream_backend.hpp>
#include <boost/log/utility/setup/file.hpp>
#include <boost/log/utility/setup/common_attributes.hpp>
#include <boost/log/utility/setup/formatter_parser.hpp>
#include <boost/log/sources/severity_logger.hpp>
#include <boost/log/sources/severity_feature.hpp>
#include <boost/log/sources/record_ostream.hpp>

#include <boost/log/attributes.hpp>

using namespace std;

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

enum severity_level
{
    DEBUG,
    INFO,
    WARNING,
    ERROR,
    CRITICAL
};

BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT(my_logger, src::severity_logger_mt< severity_level> )

// The formatting logic for the severity level
template< typename CharT, typename TraitsT >
inline std::basic_ostream< CharT, TraitsT >& operator<< (
    std::basic_ostream< CharT, TraitsT >& strm, severity_level lvl)
{
    static const char* const str[] =
    {
        "DEBUG",
        "INFO",
        "WARNING",
        "ERROR",
        "CRITICAL"
    };
    if (static_cast< std::size_t >(lvl) < (sizeof(str) / sizeof(*str)))
        strm << str[lvl];
    else
        strm << static_cast< int >(lvl);
    return strm;
}

void init() {
    // logging::register_simple_formatter_factory< severity_level >("Severity");
    logging::add_file_log(
            keywords::file_name = "blop.log",
            keywords::auto_flush = true,
            keywords::open_mode = (std::ios::out | std::ios::app),
            keywords::format = "%TimeStamp% [%Uptime%] (%LineID%) <%Severity%>: %Message%"
            );
    logging::add_common_attributes();
    logging::core::get()->add_global_attribute("Uptime", attrs::timer());
}

int main(int argc, const char *argv[]) {
    init();
    src::severity_logger_mt< severity_level > lg = my_logger::get();
    BOOST_LOG_SEV(lg, DEBUG) << "A debug severity message";
    BOOST_LOG_SEV(lg, INFO) << "An informational severity message";
    BOOST_LOG_SEV(lg, WARNING) << "A warning severity message";
    BOOST_LOG_SEV(lg, ERROR) << "An error severity message";
    BOOST_LOG_SEV(lg, CRITICAL) << "A critical severity message";
    return 0;
}

注意注释掉的行:

// logging::register_simple_formatter_factory< severity_level >("Severity");

产生上述错误。

我编译它:

g++ main.cpp -Wall -DBOOST_ALL_DYN_LINK  -lboost_system -lboost_log_setup -lboost_log -lboost_filesystem -lboost_date_time -lboost_thread -o main

最佳答案

遇到了同样的问题(日志文件中的 %Severity% 为空白，尝试添加注册函数时出现相同的编译器错误)。 我发现对 register_simple_formatter_factory 的调用应该是:

boost::log::register_simple_formatter_factory< boost::log::trivial::severity_level, char >("Severity");

关于c++ - boost 日志 2.0 : empty Severity level in logs，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15853981/