On Sunday, 29 October 2017 at 20:37:21 UTC, bauss wrote:
But casting to bool is what you use to tell whether something
is valid or not.
true = valid, false = invalid.
Not really. In mathematics 0 and 1 can be considered as "true"
and "false" for a 2-value calculus, while you might reserve ⊤ and
⊥ for true and false in the logic you use to reason about that
calculus.
Which is why some languages assumes an equality between 0 and
true and 1 and false, but that does not by necessity suggest
valid/invalid.
On the other hand. For things like Unix function call return
values -1 is often used to signify an invalid result, and 0 does
not signify failure.
So if you want strict typing, you have to do something else.
Because C (and thus D) takes the mathematical view on the
relationship between integers and bools and propagate that view
to all other basic types (e.g. floats).
Ola.
