Question

Is it possible to save STL map to file? and I can load the file to map to save time. thanks!

Answer 1

Well, you can do it manually. If not, the easiest way would be to use boost.serialization, that comes with support for all standard containers:

std::ofstream ofs("output_file");

// create class instance
std::map<int,string> whatever;

// populate map.

// save data to archive
{
    boost::archive::text_oarchive oa(ofs);
    // write map instance to archive
    oa << whatever;
    // archive and stream closed when destructors are called
}

You can see how the reverse works (reading from archive), and also that you can use also binary archives. (You’ll need a bunch of includes too, but you can get these from the documentation.)