[PD] deconstructors in pd externals

[IOhannes m zmoelnig]

Martin Peach wrote:
> Peter Worth wrote:
>> hi,
>>
>> i'm writing an external that requires a lot of memory freeing when it
>> is destroyed, but i cant find much in the way of documentation telling
>> me how to set up a deconstructor.
>>
>> at the moment i'm doing this:
>>
>> extern "C" __declspec( dllexport ) void markovchain_tilde_setup(void)
>> {
>>     markovchain_tilde_class = class_new(gensym("markovchain~"),
>>     (t_newmethod)markovchain_tilde_new,
>>     (t_method)markovchain_tilde_destroy,
>>     sizeof(t_markovchain_tilde),
[...]
>> }
>>
>> with a deconstructor like this:
>>
>> void *markovchain_tilde_destroy()
>> {
>> ....

hmm, why do you think that the free-method takes no arguments and is of
type (void*)?
i hope my oh-so-famous externals-howto does not claim such things:

"If memory is reserved dynamically, this memory has to be freed by the
destructor-method _freemethod_ (without any return argument),
when the object is destroyed."

>>
> Declare the deconstructor as
> void markovchain_tilde_destroy(t_markovchain_tilde *x)
> and keep pointer(s) to the disposable memory somewhere in x.

right.


btw, _please_ don't use the declspec constuction directly, as it will
render your code unusable (without modifications) to non-M$VC compilers.

a far better approach would be to use conditional #define's

mfg.asder
IOhannes