writing a vector of structs that contain another vector to a binary file

Question

I have been trying to write this to a file, but to no avail I have found a way, I also need to be able to read from this as well. Here is the struct

struct details
{
    float balance=0;
    vector<string> history;
    string pin;
};
struct customer
{
    int vectorID;
    string name; 
    char type;  
    details detail;
};
vector<customer> accounts;

what I have right now is:

ofstream fileBack;
fileBack.open("file.txt", ios::in|ios::binary|ios::trunc);

fileBack.write(reinterpret_cast<char*>(&accounts), accounts.size()*sizeof(accounts));
fileBack.close();

And I know this is wrong because when I open the file it is not nearly large enough to contain the information I put into it. All help appreciated, thank you in advance

Answer 1

A very easy way is to use Boost Serialization. You will need to define a member function in each of your classes to handle the serialization for example:

void details::serialize(Archive & ar, const unsigned int version) {
    ar & balance;
    ar & history;
    ar & pin;
}


void customer::serialize(Archive & ar, const unsigned int version) {
    ar & vectorID;
    ar & name; 
    ar & type;  
    ar & detail;
}

Then when you want to add to file you can just do:

std::ofstream ofs("filename", std::ios::binary); // binary file open
....
// save data to archive
{
    boost::archive::text_oarchive oa(ofs);
    // write class instance to archive
    oa << yourCustomerClass;
}

And the opposite to read the file.