Comment by turndown

I imagine you got that code snippet(or a similar example) from somewhere but to me the fairly obvious problem is the chafing between the C and C++ world. %s is for C style strings and I have to imagine that printf function is in the C world. The String(“Hello world…”) is an object in C++ world so expect weird behavior when you try to combine them. As you say in your edit, SSO will make this even weirder.