On Tuesday, 9 December 2014 at 20:24:18 UTC, Adam D. Ruppe wrote:
Also, the reason why the special function is needed is that the
argptr is just a pointer to the arguments. If you pass that to
printf, how does it know that there's varargs on the other end
instead of just being another pointer whose numeric value it is
supposed to print out?
I got it to work with vsnprintf with the following code:
___________________________________________________
import core.vararg;
import std.string : toStringz;
import std.c.stdio : printf;
char[256] buffer;
extern(C) void vsnprintf(char* s, ulong n, const(char*) format,
va_list arg);
void print(string fmt, ...)
{
char* dest = buffer.ptr;
va_list list;
va_start(list, fmt);
vsnprintf(dest, 256UL, toStringz(fmt), list);
printf(dest);
}
void main(string[] args)
{
print("%d, %d, %d\n", 1, 2, 3);
}
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I did have to declare my own function prototype because importing
vsnprintf from std.c.stdio produced the following error:
"test.d(13): Error: function core.stdc.stdio._vsnprintf (char* s,
ulong n, const(char*) format, __va_list_tag* arg) is not callable
using argument types (char*, ulong, immutable(char)*, char*)"
It works fine with my own function declaration though...
(I'm using LDC on Win64)
