Passing a value to std::ifstream through constructor

Question

I'm trying to pass a file name with a string through a constructor, my code is this. I've removed some of the unnecessary stuff for simplicity.

// header file

Interpreter(const std::string location);
std::ifstream *file;

// end header file

// class file

Interpreter::Interpreter(const std::string location) {
    file = new std::ifstream(location.c_str());
}

// end class file

However, the result is a "Debug Assertion Failed!".

image

Edit: As a fairly newbie C++ programmer (came from Java), I've taken the advice of an initializer list and this is my code now (in the header):

std::ifstream file;

Interpreter(const std::string location) {
    file.open(location.c_str());
}

Yet I'm still getting the same error, any help? Thanks!

Edit 2:

int main(int argc, char** argv) {
    Interpreter *interpreter = nullptr;

    // check if arguments are provided
    if (argc > 0) {
        interpreter = new Interpreter(argv[1]);
    } else {
        // for now just use the debug script
        error("No input files, using default script (debug)");
        interpreter = new Interpreter("test.m");
    }

    interpreter->read();
    delete interpreter;

    return 0;
}

Edit 3

Did you mean this initializer list?

Interpreter::Interpreter(const std::string location): file(location) {    
}

Edit 4

Final edit, thanks guys :) Turns out the problem was with the arguments

And argc>0 does not mean argv[1] is safe to access.

That's in the CPP file, and still gives the same result. D:

Answer 1

if (argc > 0) {
    interpreter = new Interpreter(argv[1]);

This is not correct, if argc == 1 then argv[1] is out of bounds, it should be

if (argc > 1) {
    interpreter = new Interpreter(argv[1]);

As for the rest of the question, I would write the constructor like this:

Interpreter(const std::string location) : file(location) { }

(In C++11 you can construct an fstream from a std::string, if that doesn't work with your compiler then use location.c_str() as you had previously:

Interpreter(const std::string location) : file(location.c_str()) { }

I would write your main function like this:

int main(int argc, char** argv)
{
    std::string file;
    // check if arguments are provided
    if (argc > 1) {
        file = argv[1];
    } else {
        // for now just use the debug script
        error("No input files, using default script (debug)");
        file = "test.m";
    }

    Interpreter interpreter(file);
    interpreter.read();
}

This has no new and delete and is simpler and clearer.