Hi All,
In the following piece of code:
use NativeCall;
class CupsDest is repr('CStruct') {
has Str $.name;
has Str $.instance;
has int32 $.is-default;
has Pointer $.options;
}
sub cupsGetDests(Pointer is rw --> int32) is native('cups', v2) {}
Would some kind soul please explain to me
what is going on line by line with the "class"
statement.
cupsGetDests definition can be found at:
https://www.cups.org/doc/cupspm.html <https://www.cups.org/doc/cupspm.html>
I am confused. Yes, again.
-T
On 12/8/20 7:42 AM, Andy Bach wrote:
> Would some kind soul please explain to me what is going on line by
line with the "class" statement.
> cupsGetDests definition can be found at:
https://www.cups.org/doc/cupspm.html <https://www.cups.org/doc/cupspm.html>
The point of the class is to create a "template" in raku matching the C
structure of the cups stuct. That way, when passed to "nativecall"
https://docs.raku.org/routine/nativecast
<https://docs.raku.org/routine/nativecast>
it can use that template to understand what the pointer is pointing to
(i.e. the cups cstruct).
my $dest = nativecast(CupsDest, Pointer.new($ptr + $i *
nativesizeof(CupsDest)));
The "nativesizeof" gives the size of the struct, so the
$ptr + $i * nativesizeof(CupsDest)
moves the new Pointer down the list one struct at a time.
Hi Andy,
I guess what I am missing is how
int cupsEnumDests(unsigned flags, int msec, int *cancel, cups_ptype_t
type, cups_ptype_t mask, cups_dest_cb_t cb, void *user_data);
matches up with
class CupsDest is repr('CStruct') {
has Str $.name;
has Str $.instance;
has int32 $.is-default;
has Pointer $.options;
}
I also do not understand what the dot is doing in "$.name".
And exactly what is `repr('CStruct')`?
:'(
-T
