Unexpected results with std::ofstream binary write

Question

I\'m new to C++ std::stream and I\'m making some tests. I have this simple code:

int i = 10;
char c = \'c\';
float f = 30.40f;

std::ofstream out(\"test.txt\         


        

Answer 1

In order to write raw binary data you have to use ostream::write. It does not work with the output operators.

Also make sure if you want to read from a binary file not to use operator>> but instead istream::read.

The links also provide examples how you can handle binary data.

So for your example:

int i = 10;
char c = 'c';
float f = 30.40f;

std::ofstream out("test.txt", std::ios::binary | std::ios::out);
if(out.is_open())
{
    out.write(reinterpret_cast(&i), sizeof(i));
    out.write(&c, sizeof(c));
    out.write(reinterpret_cast(&f), sizeof(f));
    out.close();
}