c++ - When creating a vector of objects, how to pass arguments to Default or Copy Constructor to initialize values? -

for program i'm writing project in c++ class, 1 of requirements use constructors initialize data members in objects.

we have read binary files.

the method chose accomplish was:

// loads invmast.dat or creates 1 if none exists fstream invfile; invfile.open("invmast.dat", std::fstream::in); if (!invfile) {     cout << "file invmast.dat not found, creating new one." << endl;     invfile.open("invmast.dat", std::fstream::out | std::fstream::app | std::fstream::binary);     if (!invfile)     {         cerr << "unable create or open file invmast.dat; exiting." << endl;         exit (exit_failure);     } } cout << "file invmast.dat opened successfully." << endl;  vector <inventoryitem> invmast; //vector <inventoryitem>::iterator invmastiterator;  inventoryitem invloader;  while ( invfile && !invfile.eof()) {     invfile.read(reinterpret_cast<char *>(&invloader), sizeof(invloader));     invmast.insert(invmast.begin(), invloader);       } 

i'd prefer create vector of objects , pass arguments copy or default constructor, can't seem find way this.

is there way, or need rethink approach?

thanks!

if constructing element, use emplace_back construct directly in vector:

invmast.emplace_back(some, constructor, parameters); 

but here, since you’re initialising inventoryitem raw bytes, want construct object , move vector:

invfile.read(reinterpret_cast<char *>(&invmast.back()), sizeof(invloader)); invmast.push_back(std::move(invloader)); 

or default-construct element , fill it:

invmast.emplace_back(); invfile.read(reinterpret_cast<char *>(&invmast.back()), sizeof(inventoryitem));