This question was asked on twitter.
So here is a basic code snippet:
#include <iostream>
void main() {
cout << "Hello wolrd" << endl;
}
To be able to post this, all you need to do is, choose the new editor from "Settings->Basic -> Post Editor".
In the post options at the bottom of the Post Editor make sure, you have the "Show HTML literally" chosen in Compose Settings".
Extra tip: If you copy paste code from some website with nice formated colors, the code will show up exactly alike on your post.