On 08/06/2013 01:01 AM, andrea9940 wrote:
> Hi, I'm working with the X11 library available from
> https://github.com/D-Programming-Deimos/libX11
> If I try to call XSynchronize(display, True) the compilation fails with
> "Error: function deimos.X11.Xlib.XSynchronize (_XDisplay*) is not
> callable using argument types (_XDisplay*, int)"
>
> I am sure the arguments are correct (see http://goo.gl/8Hzn8s for
> example) so I think there is a conversion problem between the C and D
> definition of the function:
>
> --- Xlib.h
> extern int (*XSynchronize(
> Display* /* display */,
> Bool /* onoff */
> ))(
> Display* /* display */
> );
I have written the following stubs for C:
typedef void Display;
typedef int Bool;
extern int (*XSynchronize(
Display* /* display */,
Bool /* onoff */
))(
Display* /* display */
);
typedef int(*PreviousAfterFunction)(Display*);
int previous_after_foo(Display* display)
{
return 0;
}
PreviousAfterFunction XSynchronize(Display* display, Bool onoff)
{
return &previous_after_foo;
}
int main()
{
int (*paf)(Display*) = XSynchronize(0, 1);
paf(0);
}
And then I have written the direct translation in D, which works as well:
struct Display
{}
alias PreviousAfterFunction = int function(Display*);
int previousAfterFoo(Display *)
{
return 0;
}
PreviousAfterFunction XSynchronize(Display*, bool)
{
return &previousAfterFoo;
}
void main()
{
PreviousAfterFunction paf = XSynchronize(null, 1);
paf(null);
}
> --- Xlib.d
> extern int function(
> Display* /* display */,
> Bool /* onoff */
> )XSynchronize(
> Display* /* display */
> );
It looks like Xlib.d got it backwards: XSynchronize takes two parameters
and returns a function pointer that takes a single parameter. It should
be the following:
int function(Display*) XSynchronize(Display*, bool);
> Also I can't understand why the C version is not "extern int
> XSynchronize(Display*,
> Bool);" which would be the simplest definition.
That's different. That would be a function taking two parameters and
returning int. However, XSynchronize takes two parameters and return a
function pointer (that takes one parameter and returns an int).
Ali
