I've certainly found C++ bool helpful, in terms of readability and self-documentation, and the general positive clarifying effects of making sure you've got you

I've certainly found C++ bool helpful, in terms of readability and self-documentation, and the general positive clarifying effects of making sure you've got your types straight (to the extent that C++ gives you any help with that). C++ bool does the right thing, as far as turning values into true or false goes (the cast effectively does a "!=0", making the result exactly 1 or 0). I believe that C99 _Bool behaves in the same way in this respect - so that would be doing the right thing too. (One issue with "native" bools, that others have pointed out, is that it's possible to introduce bugs due to implicit conversions. But I've personally found this behaviour usually to be what you want, and I don't remember having to fix any bugs caused by it, suggesting that they can't have been all that difficult to sort out.) His point about casting to fake bool types is well made, and I wonder how many instances of this I will now spot? (gcc appears to issue perfectly fine warnings for this case, though.) Another argument for using the built-in types, in my view. Or for switching to "typedef uintptr_t bool".