... bound therefore to generate the most discussion ...
> C99 introduced _Bool as a builtin type. The gcc patch for
> it went into cvs around Dec 2000. Any objections to
> propagating this type and usage of 'true' and 'false' around
> the kernel?
What concerns me is the question of casting. Will truth always
cast to integer value 1 and falsehood always cast to integer
value 0, and vice versa? If so then the bool type is a lot
like a "bit" type would be if C had one, i.e., a very short
integer variable limited to the values 0 and 1. If the casts
are not guaranteed then bool is a lot like an enumerated type
where the compiler is free to choose whatever representations
it wants for truth and falsehood.
I assume the casts are guaranteed. E.g., I take it that the
result of a logical comparison is considered to be of type
bool, but that the following will increment val by 1 if a > b
val += (a > b)
In that case, perhaps it would be more perspicuous to define
a "bit" type rather than a "bool" type, and to use 0 and 1 as
its values rather than 'true' and 'false'. (A "bit" type
would have all the advantages mentioned earlier by Peter Anvin
http://marc.theaimsgroup.com/?l=linux-kernel&m=101191106124169&w=2 .)
-- Thomas Hood- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/