Question

I am interested in sharing data between Java and C++ so JNI. Currently all the C++ code expects a file so its all written in terms of std::ifstream. Rather than writing the files and reading them again, I would like to be able to just pass a char* over and have the application read from that instead somehow treating the char* as a ifstream. Is there anyway to create a ifstream that is based on a char* ?

Thanks

Answer 1

Yes, it’s called std::istringstream. You can use it like this:

#include<sstream>

....

char const* s = "whatever";

std::istringstream iss(std::string(s));

int i;

iss >> i;

....

If your code expects a std::ifstream specifically, you could change it to expect a generic std::istream, from which both inherit, as Adrian mentioned.