Re: NativeCall -- size of data structure

nativesizeof is what I was looking for.

Thanks,

~Paul


On Sat, Jan 2, 2021 at 8:39 PM ToddAndMargo via perl6-users <
perl6-users@perl.org> wrote:

> On 1/2/21 4:58 PM, Paul Procacci wrote:
> > Hey Gents,
> >
> > Hopefully a simple question that I could not find the answer to.
> >
> > Given the following:
> >
> > class PROCESSENTRY32 is repr('CStruct') {
> >      has int32 $.dwSize;
> >      has int32 $.cntUsage;
> >      has int32 $.th32ProcessID;
> >      has Pointer $.th32DefaultHeapID;
> >      has int32 $.th32ModuleID;
> >      has int32 $.cntThreads;
> >      has int32 $.th32ParentProcessID;
> >      has long $.pcPriClassBase;
> >      has int32 $.dwFlags;
> >      HAS Str @.szExeFile[260] is CArray;# MAX_PATH on windows is 260
>
> Did you mean to capitalize the HAS?
>
> > };
> >
> >
> > ... is there is a raku method that gives me the size of this data
> structure?
> >
> > In C for example one would use sizeof() to provide the size.  In raku I
> > could not find the documentation that would provide this information.
> >
> > Thanks,
> > Paul Procacci
>
> Hi Paul,
>
> Not that I know of.  Raku has a lot of things in
> the background of its structures that C does not.
>
> C does not have OOP (object orientated programming)
> but does have "struct", which is close enough.
>
> What you are trying to do is match the C structure
> of the system call with Raku's OOP "class".  In Raku,
> "class" is the definition of a structure and not the
> structure itself -- very much like C's "struct".
>
> You don't get an actual structure until you
> declare one from the class.  For example:
>
>      my $x = PROCESSENTRY32.new;
>
> And it is going to be a lot bigger behind the scenes
> that just adding up the bits.  You really do not need
> to know the behind the scene details anyway.  Raku
> strives to remove the need for the programmer to
> have to know these kind of details, unlike C.
>
> What system call are you trying to run?
>
> I have an example of how to read Windows Time
> that also uses OOP (class, object, and method).
> Let me know if you want it
>
> -T
>
>
>
>

-- 
__________________

:(){ :|:& };:

• NativeCall -- size of data structure by Paul Procacci
• Re: NativeCall -- size of data structure by ToddAndMargo via perl6-users
• Re: NativeCall -- size of data structure by Paul Procacci
• Re: NativeCall -- size of data structure by Paul Procacci