What breaks? (was Re: 64 bit longs?)

[David Tanguay]

In article <1991Jan18.044948.27943 at zoo.toronto.edu> henry at zoo.toronto.edu (Henry Spencer) writes:
>In article <14890 at smoke.brl.mil> gwyn at smoke.brl.mil (Doug Gwyn) writes:
>>There is no portable way to declare any integral type constrained to use
>>precisely 32 bits in its representation.
>
>There is no portable way to declare a type with *exactly* 32 bits, and
>a TCP/IP sequence number (for example) is exactly 32, no more.

How about: (Standard C only)

typedef struct { long it:32; } net32_t;
#define net32_t(var) var.it

and then all accesses to variables are wrapped in net32_t(var).

	void
happy( void )
{
	net32_t it;

	...
	net32_t(it) = 123456;
	++net32_t(it);
	net32_t(some_global) = net32_t(it) + 42;
	...
}

I don't like sticking the 32 in the type name, since that may change,
so just consider the above as an illustration of a technique.
Ugly, I think, but it should accomplish what you want.
-- 
David Tanguay            Software Development Group, University of Waterloo