> You can't call that a C "bool" though. In hardware, C _Bool is just an scalar integer type (1 byte wide almost everywhere these days). If you define 0 for f

> You can't call that a C "bool" though. In hardware, C _Bool is just an scalar integer type (1 byte wide almost everywhere these days). If you define 0 for false, and true otherwise, you can emit much better machine code for all scalar comparisons. For example, when doing scalar == 0 or scalar != 0 (e.g. in null pointer checks) the result is always the scalar itself. The test is a nop, and with "branch on non-zero" instruction, you can just directly branch. If you define true to some value, you need to actually test whether the scalar is zero, and give it some other value otherwise. That goes from zero instructions to often two instructions (e.g. if the hardware comparison returns 0xffff and you need to convert that to 1).