Purpose of exception on some methods?

[Gounlaf]

👋

I'm not used to C/C++, so my question may be dumb

In the below snippet, I don't understand what the exception is used for:

MAGICK_NATIVE_EXPORT ssize_t MagickImage_ColormapSize_Get(const Image *instance, ExceptionInfo **exception)
{
  (void) exception;

  if (instance->colormap == (PixelInfo *) NULL)
    return -1;

  return (ssize_t) instance->colors;
}

What I understand is that it's not used, but I'm not sure.
In that case, could the API be simplified?

Regards.

[dlemstra]

This has to do with the fact that the MagickImage_ColorSpace_Set requires exception. The code generation can only set that exception for both the get and set. I will probably change the code generator in the future and maybe I can make this possible then but for now you need to pass it.