使用boost库来计算文件夹的大小

#include <boost/cstdint.hpp>
#include <algorithm>
#include <boost/filesystem.hpp>
#include <boost/bind.hpp>
#include <boost/iterators/transform_iterator.hpp>
namespace fs = boost::filesystem;

boost::uintmax_t dir_size( const fs::path &p)
{
 return std::accumulate(
   boost::make_transform_iterator(&fs::file_size, fs::recursive_directory_iterator(p)),
   boost::make_transform_iterator(&fs::file_size, fs::recursive_directory_iterator()),
   static_cast <boost::uintmax_t>(0));
}