On Thursday, 28 June 2018 at 18:10:07 UTC, kdevel wrote:
On Tuesday, 26 June 2018 at 21:54:49 UTC, Jonathan M Davis
wrote:
[H]onestly, I don't understand why folks keep trying to put
nullable types in Nullable in non-generic code.
How do you signify that a struct member of class type is
optional?
So there're no optional type in D (ala Swift, Kotlin, Scala,
etc). There are a number of workarounds you can use to achieve
the same type of behavior.
You can use ranges to denote "some" value or no value (empty
range). But it's a bit inconvenient and the APIs to get that
running say nothing about intent.
You can create a lightweight Maybe type:
https://stackoverflow.com/questions/27241908/maybe-types-in-d
I've implemented an optional type as well that includes safe
dispatching, but it's not @nogc right now ->
https://github.com/aliak00/optional
I think there's another optional type on dub somewhere as well.
But using Nullable!T just defers the problem that optional solves:
if (nullable.isNull) {
nullable.get.doSomething();
}
vs:
if (ptr !is null) {
ptr.doSomething();
}
meh...
It's more of a tool to allow you to give any type nullability
semantics.
Cheers,
- Ali
