Functional syntax (Was: RE: [mercury-users] Hi, and determini sm)

[Fergus Henderson]

On 08-Feb-2001, Richard A. O'Keefe <ok at atlas.otago.ac.nz> wrote:
> 	struct { int a:7, b:5, c:4; } x;
> 	...
> In this little example, both packed records would be 32 bits, so
> there would be no space advantage to the tighter packing.  (Yes, I know
> there are 16 bits, but most C compilers make records a multiple of 32 bits
> anyway.)

GNU C will make that 16 bits if you use

 	struct { short a:7, b:5, c:4; } x;

Allowing `short' bitfields is an extension to standard C.
But it's not hard to make such uses conditional, e.g.

	#ifdef __GNUC__
	  typedef short short_bitfield;
	#else
	  typedef int short_bitfield;
	#endif

 	struct { short_bitfield a:7, b:5, c:4; } x;

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "I have always known that the pursuit
                                    |  of excellence is a lethal habit"
WWW: <http://www.cs.mu.oz.au/~fjh>  |     -- the last words of T. S. Garp.
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