A useful construct for C !

[Chuck Collins]

I have often felt the need for a "typeof" operator, and in cases that
cannot readily be taken care of by typedef. Consider:

	#include	<sgtty.h>

	struct	sgttyb	get;

	saveflags(flags)
	(typeof get.sg_flags)	flags;
	{

This provides a clean way of making two data items match. You wouldn't
suggest that I open up sgtty.h and add a typedef. This example seems
trivial, but I've run into it in much more practical situations.