On Wednesday, 21 November 2018 at 21:05:37 UTC, aliak wrote:
On Wednesday, 21 November 2018 at 17:46:29 UTC, Alex wrote:
compiled against 4.6.1 Framework.
However, of course, there is a NullReferenceException, if c
happens to be null, when calling baz.
So the difference is not the compiler behavior, but just the
runtime behavior...
How could the compiler know the state of Random anyway, before
the program run.
The compiler would not be able to prove that something was
initialized and hence could give an error. Maybe c# doesn't do
it but swift certainly does:
class C {
func baz() {}
}
func f() {
var x: C
if Int.random(in: 0 ..< 10) < 5 {
x = C()
}
x.baz()
}
error: variable 'x' used before being initialized
Nice! Didn't know that... But the language is a foreign one for
me.
Nevertheless, from what I saw:
Shouldn't it be
var x: C?
as an optional kind, because otherwise, I can't assign a nil to
the instance, which I can do to a class instance in D...
and if it is, it works in the same manner as C#, (tried this out!
:) )
Comparing non-optional types from swift with classes in D is...
yeah... hmm... evil ;)
And if you assume a kind which cannot be nil, then you are again
with structs here...
But I wondered about something different:
Even if the compiler would check the existence of an assignment,
the runtime information cannot be deduced, if I understand this
correctly. And if so, it cannot be checked at compile time, if
something is or is not null. Right?
