I wrote:
> gaur/pademelon isn't booted up right now, but it might provide
> an example of a system that lacks <stdbool.h> altogether.
> (If it doesn't, I'd be willing to concede that we need not
> consider that scenario anymore.)
For the record --- pademelon (vendor cc on that box) doesn't have
<stdbool.h> at all. gaur (user-installed gcc) has such a header,
but it contains
typedef enum { false = 0, true = 1 } bool;
which unsurprisingly results in
sizeof(bool) = 4
What's possibly more relevant to Peter's patch, this represents
a platform on which "#include <stdbool.h>" succeeds, but
(a) there is no typedef _Bool, and (b) "bool" is not a macro.
Obviously pre-C99 ...
regards, tom lane