使用Boost的Log库，将日志信息写入文件，日志将按时间滚动。详见代码：

#include <boost/date_time/posix_time/posix_time_types.hpp>
#include <boost/log/core.hpp>
#include <boost/log/expressions.hpp>
#include <boost/log/sinks/sync_frontend.hpp>
#include <boost/log/sinks/text_ostream_backend.hpp>
#include <boost/log/sources/record_ostream.hpp>
#include <boost/log/sources/severity_logger.hpp>
#include <boost/log/support/date_time.hpp>
#include <boost/log/utility/setup/file.hpp>
#include <boost/log/utility/setup/common_attributes.hpp>
#include <boost/log/trivial.hpp>namespace logging = boost::log;
namespace sinks = boost::log::sinks;
namespace src = boost::log::sources;
namespace expr = boost::log::expressions;
namespace attrs = boost::log::attributes;
namespace keywords = boost::log::keywords;void init_log_lib()
{auto sink = logging::add_file_log(keywords::file_name = "%Y%m%d_%4N.log",keywords::rotation_size = 5 * 1024 * 1024,keywords::time_based_rotation = sinks::file::rotation_at_time_point(23,59,59),keywords::format = (expr::stream<< expr::format_date_time<boost::posix_time::ptime>("TimeStamp","%Y-%m-%d %H:%M:%S") << " <" <<logging::trivial::severity<<"> "<<expr::smessage));sink->locked_backend()->set_file_collector(sinks::file::make_collector(keywords::target = "./logs",keywords::max_size = 500*1024*1024,keywords::min_free_space = 800*1024*1024));sink->locked_backend()->auto_flush(true);sink->locked_backend()->scan_for_files();logging::core::get()->set_filter(logging::trivial::severity >= logging::trivial::trace);logging::add_common_attributes();
}void close_log_lib()
{logging::core::get()->remove_all_sinks();
}void log_msg(const std::string& msg)
{src::severity_logger_mt<logging::trivial::severity_level> lg;BOOST_LOG_SEV(lg, logging::trivial::info) << msg;
}int main()
{init_log_lib();log_msg("Hello World!\n");close_log_lib();return 0;
}