For backward compatibility with pre-standard C.
A bit too much search/replace during porting.
It depends on the language projection.
Some manual cleanup.
You can also take more proactive steps.
Well, one way is to poll for it.
Going back to the old standby to filter out unwanted specializations.
Finding a template metaprogramming trick that works.
Hunting for the right template metaprogramming trick.
Teasing out the calling convention from a function pointer.