[go-nuts] CGo error : Cannot use GoCallback (type func(_Ctype_int, unsafe.Pointer)) as type *[0]byte in function argument

Hi all,

I'm trying to call a Go function from C using CGo. The function shall
accept a char** argument.
The following code exemplifies what I'm trying to do:


package main

//
// typedef void (*Callback)(int argnum, char **args );
// void CallMe( Callback f ) {
// char *args[2] = { "Ciao", "mondo" };
// f(2, args);
//
//}
import "C"
import "unsafe"

func GoCallback( argnum C.int, args unsafe.Pointer ) {
// Convert args and do stuff
}


func main() {
C.CallMe(GoCallback)
}


I get the following error :

*Cannot use GoCallback (type func(_Ctype_int, unsafe.Pointer)) as type
*[0]byte in function argument*

How comes a C function pointer becomes a *[0]byte ( which should translate
to "pointer to a zero-length array of bytes" ) ??

P.S : Doing C.CallMe(C.Callback(GoCallback)) gives the following error,
which is less puzzling but does not explain much:

*cannot convert GoCallback (type func(_Ctype_int, unsafe.Pointer)) to type
C.Callback *


Thanks in advance for any help

Ciao
---
FB