我如何使用Boost.Filesystem更改当前路径

int main()
{
   cout << current_path() << \'\\n\'; // c:\\workspace\\projects
   current_path(\"c:\\\\program files\");
   cout << current_path() << \'\\n\';  // c:\\program files
}

boost::filesystem::path full_path( boost::filesystem::current_path() );
std::cout << \"Current path is : \" << full_path << std::endl;
//system(\"cd ../\"); // change to previous dir -- this is NOT working
chdir(\"../\"); // change to previous dir -- this IS working
boost::filesystem::path new_full_path( boost::filesystem::current_path() );
std::cout << \"Current path is : \" << new_full_path << std::endl;