...the public visibility wouldn't truly be public, and since the functions would be public...

...d
import core.stdc.stdarg;

pragma(printf)
public extern(C) int wrap_printf(scope const...

...void va_end(void* ap){}

pragma(printf)
public extern(C) int wrap_printf(scope const...

...d
import core.stdc.stdarg;

pragma(printf)
public extern(C) int wrap_printf(scope const...

basically the only solution is
cstats.stamina += 1;

...null;
              break;
          }
        }
        *resp = responses;
        return PAM_SUCCESS;
      }
    }

  public:
    int authenticate(string username, string password)
    {
      if...

I love it! intuitive (unlike most of the other suggestions).

...null;
                        break;
                }
            }

            *resp = responses;

            return PAM_SUCCESS;
        }
    }
public:
    int authenticate(string username, string password) {
        if...

...conversation_func` to call it inside the public authentication function. When compiling I get this...

...strdup;
import core.stdc.stdlib : malloc, free;
public import std.stdio;

struct pam_data { string...