> 1. Explicitly set the C standard to C17 or older, so the code is built using the custom boolean type.
> Option 1) seemed like the easiest one, but it also felt a bit like kicking the can down the road – plus, it introduced the question of which standard to use.
Arguably, that's the sanest one: you can't expect the old C code to follow the rules of the new versions of the language. In a better world, each source file would start with something like
#pragma lang_ver stdc89
and it would automatically kick off the compatibility mode in the newer compilers, but oh well. Even modern languages such as Go miss this obvious solution.
On the topic of the article, yeah, sticking anything other than 0 or 1 into C99 bool type is UB. Use ints.
> Option 1) seemed like the easiest one, but it also felt a bit like kicking the can down the road – plus, it introduced the question of which standard to use.
Arguably, that's the sanest one: you can't expect the old C code to follow the rules of the new versions of the language. In a better world, each source file would start with something like
and it would automatically kick off the compatibility mode in the newer compilers, but oh well. Even modern languages such as Go miss this obvious solution.On the topic of the article, yeah, sticking anything other than 0 or 1 into C99 bool type is UB. Use ints.