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There are ABIs where this is > > > not the case. > > > > Hi Peter, > > > > Do you have a concrete example on which ABI/arch this is not true? > > > > I know that the C spec doesn't mandate _Bool and char are of the same size > > but we have tons of assumptions that is not guaranteed by standard C.. > > Darwin/PowerPC famously has sizeof(_Bool) == 4 > > Win32: Visual C++ 4.2 (and earlier) had sizeof(bool)==4 (they mapped > bool to int), while Visual C++ 5.0 introduced a native _Bool and moved > to 1 byte. > > Early RISC CPUs (MIPS, PowerPC, Alpha) had severe penalties for byte > access and their compilers would've had sizeof(bool)=={4,8}. > > I think AVR/Arduino also has sizeof(bool) == sizeof(int) which is 2. > > It sounds like that none of these matter for the kernel? In which case I think it's good to keep the assertion; if someone is ought to introduce a new arch where _Bool (or Rust bool) is not 1 then we should know about it. Best, Gary