C to D conversion for function

[Sumit Raja]

Hi,

I wanted some help in converting this
void av_log_ask_for_sample(void *avc, const char *msg, ...) 
av_printf_format(2, 3);

from C to D.

I don't know what it means or is called in C to start with so I 
am a bit lost on what to search for.

Thanks

Sumit