Question

I understand that startup_info is a pointer to a STARTUPINFO structure

I have a function which I pass startup_info by reference into it. So we can say that I am passing a pointer by reference

void cp(....., LPSTARTUPINFO & startup_info) {
  CreateProcessW(....., startup_info);
}

Let us assume that I call function cp in this function caller()

void caller() {
  STARTUPINFO startup_info; 
  cp(....., startup_info); // error occurs here, I cannot convert 'STARTUPINFO' to 'LPSTARTUPINFO &'
}

It will give me error message: Error in CreateProcessW: cannot convert parameter 9 from ‘STARTUPINFO’ to ‘LPSTARTUPINFO &’

But since statup_info is a pointer, I should be able to pass this into function cp right?

EDIT:
Thank you for your advices,but the following works for me:
LPSTARTUPINFO is a pointer to STARTUPINFO structure

So I change to

void cp(....., LPSTARTUPINFO startup_info_ptr) {
      CreateProcessW(....., startup_info_ptr); // pass in pointer of startup_info
}

void caller() {
      STARTUPINFO startup_info; 
      cp(....., &startup_info); // passing the address of startup_info
}

Answer 1

You’ve got two startup_info‘s. In caller(), it’s a STARTUPINFO (not a pointer). In cp(), it’s a STARTUPINFO*& (reference to a pointer). Why? It’s most likely unintentional.

I’d expect:

void cp(....., STARTUPINFO* pStartup_info) {
  CreateProcessW(....., pStartup_info);
}
void caller() {
  STARTUPINFO startup_info; 
  cp(....., &startup_info);
}

In production code, I avoid p prefixes for pointers but I’ve used it here to disambiguate the two startup_info‘s which you had.