Being a relatively old-timer with D, I feel slightly embarassed about asking this, but I humbly submit:

How does one call a variadic-function in D with the variadic arguments presented to the calling function?

: int error_log(...) {
:   return writef(...);
: }

I seem to have tried all variants of passing combinations of _argptr, _arguments along, with no success.

Regards,
James Dunne

Can you actually do this in D ?

In C you woudnt, unless writef has from writef(va_list ap)
		error_log(...)
		{
			writef(va_list ap);
		}


:$

On Sun, 22 May 2005 19:34:16 +0000 (UTC)
James Dunne <james.jdunne@gmail.com> wrote:

> Being a relatively old-timer with D, I feel slightly embarassed about asking this, but I humbly submit:
> 
> How does one call a variadic-function in D with the variadic arguments presented to the calling function?
> 
> : int error_log(...) {
> :   return writef(...);
> : }
> 
> I seem to have tried all variants of passing combinations of _argptr, _arguments along, with no success.
> 
> Regards,
> James Dunne

There has to be a target method/function signature along the following lines:

#  void format (TypeInfo[] arguments, va_list argptr)

This will accept the implicit parameters _arguments and _argptr of the calling function. I expect std.format does something like this.

- Kris


"James Dunne" <james.jdunne@gmail.com> wrote in message news:d6qmro$2eh2$1@digitaldaemon.com...
> Being a relatively old-timer with D, I feel slightly embarassed about
asking
> this, but I humbly submit:
>
> How does one call a variadic-function in D with the variadic arguments
presented
> to the calling function?
>
> : int error_log(...) {
> :   return writef(...);
> : }
>
> I seem to have tried all variants of passing combinations of _argptr,
_arguments
> along, with no success.
>
> Regards,
> James Dunne

nice

On Sun, 22 May 2005 14:21:44 -0700
"Kris" <fu@bar.com> wrote:

> There has to be a target method/function signature along the following lines:
> 
> #  void format (TypeInfo[] arguments, va_list argptr)
> 
> This will accept the implicit parameters _arguments and _argptr of the calling function. I expect std.format does something like this.
> 
> - Kris
> 
> 
> "James Dunne" <james.jdunne@gmail.com> wrote in message news:d6qmro$2eh2$1@digitaldaemon.com...
> > Being a relatively old-timer with D, I feel slightly embarassed about
> asking
> > this, but I humbly submit:
> >
> > How does one call a variadic-function in D with the variadic arguments
> presented
> > to the calling function?
> >
> > : int error_log(...) {
> > :   return writef(...);
> > : }
> >
> > I seem to have tried all variants of passing combinations of _argptr,
> _arguments
> > along, with no success.
> >
> > Regards,
> > James Dunne
> 
> 

In article <d6qmro$2eh2$1@digitaldaemon.com>, James Dunne says...
>
>Being a relatively old-timer with D, I feel slightly embarassed about asking this, but I humbly submit:
>
>How does one call a variadic-function in D with the variadic arguments presented to the calling function?
>
>: int error_log(...) {
>:   return writef(...);
>: }
>
>I seem to have tried all variants of passing combinations of _argptr, _arguments along, with no success.
>
>Regards,
>James Dunne

James, I know this isn't exactly what you asked for, but since you're going to print the error within the error_log function, it makes sense to me that it should be formatted and then printed there. So maybe the code I wrote below might do the job for your current problem.

# // errorlog.d
# private import std.stdio;
# private import std.format;
# private import std.utf;
#
# uint error_log(...)
# {
#     char[]  s;
#     dchar[] ds;
#
#     void add2Buffer( in dchar dc )
#     {
#         ds.length = ds.length + 1;
#         ds[ ds.length - 1 ] = dc;
#     }
#
#     std.format.doFormat( &add2Buffer, _arguments, _argptr );
#
#     s.length = ds.length;
#     s = std.utf.toUTF8(ds);
#
#     writef(s);
#     return s.length;
# }
#
# int main()
# {
#     int iMsgLen;
#
#     iMsgLen = error_log("error: Found ", 123.45,
#                         ", was expecting a non-floating point number.");
#     writefln();
#     writefln("iMsgLen=%d", iMsgLen);
#     return 0;
# }

Output:
---------
C:\dmd>dmd errorlog.d
C:\dmd\bin\..\..\dm\bin\link.exe errorlog,,,user32+kernel32/noi;

C:\dmd>errorlog
error: Found 123.45, was expecting a non-floating point number.
iMsgLen=63

C:\dmd>

Hope you find the code useful,
David L.

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James Dunne wrote:
> Being a relatively old-timer with D, I feel slightly embarassed about asking
> this, but I humbly submit:
> 
> How does one call a variadic-function in D with the variadic arguments presented
> to the calling function?
<snip>

Known issue.

http://www.digitalmars.com/drn-bin/wwwnews?digitalmars.D/11282

Stewart.

-- 
My e-mail is valid but not my primary mailbox.  Please keep replies on the 'group where everyone may benefit.

> #  void format (TypeInfo[] arguments, va_list argptr)

Maybe this can be changed to use the newly added Box?
void format( Box[] arguments );

Which means:

* Box[] can be created implicitely when calling a function with ... :
format(2,3,"test") will created a Box[] with 3 elements and passing it to
format(...)

* a Box[] can be passed to a function for the "..."
my_format( ... ) { format(arguments); }

L.