C++ Boost lib to scan directory

library(-l) : boost_system boost_filesystem 
Include(-I) : /usr/include/boost

#include <boost/filesystem.hpp>

namespace fs = boost::filesystem;

std::string dirPath = "/home/darrenl/Pictures/person";
fs::path someDir(dirPath);
fs::directory_iterator end_iter;

typedef std::multimap<std::time_t, fs::path> result_set_t;
result_set_t result_set;

if (fs::exists(someDir) && fs::is_directory(someDir)) {
    for (fs::directory_iterator dir_iter(someDir); dir_iter != end_iter;
            ++dir_iter) {
        if (fs::is_regular_file(dir_iter->status())) {
            result_set.insert(
                    result_set_t::value_type(
                            fs::last_write_time(dir_iter->path()),
                            *dir_iter));
            LOG(INFO)<< dir_iter->path().string();

        }
    }
}