Messages in this thread | | | Date | Fri, 25 Jan 2002 16:07:50 +0100 | From | Werner Almesberger <> | Subject | Re: RFC: booleans and the kernel |
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H. Peter Anvin wrote: > c) The ability to cast to bool and get an unambiguous true or false: > > b = (bool)a; > > This replaces the idiomatic but occationally confusing > > b = !!a;
Careful, though. This example
#include <stdbool.h> #include <stdio.h>
int main(void) { int foo;
foo = (bool) 4; printf("%d\n",foo); return 0; }
e.g. compiled with gcc "2.96" (RH 7.1, 2.96-85), yields 4.
Not sure if this is a flaw of gcc or of the standard. If gcc's stdbool.h is a standard-compliant implementation of "bool", then K&Rv2 seems to endorse this behaviour: from A4.2, "Enumerations behave like integers".
- Werner
-- _________________________________________________________________________ / Werner Almesberger, Lausanne, CH wa@almesberger.net / /_http://icawww.epfl.ch/almesberger/_____________________________________/ - 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/
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