On Friday, 17 July 2015 at 12:18:56 UTC, TC wrote:
Hello,
I came around a strange behavior and I'm not sure if it is a
bug or feature.
import std.typecons : Nullable;
struct Foo
{
string bar;
Nullable!int baz;
}
auto a = Foo("bb");
auto b = Foo("bb");
assert(a == b);
This ends up with: Called `get' on null Nullable!int
But if I change bar to be an int for example, than it passes ok.
I would expect this to pass ok.
Tested on dmd 2.067.1 win64
what is happening is the complier generated default opEquals is
accessing the payload for Nullable!T without checking for null
(which as you've written `Foo("bb")` this constructs a and b as
`Foo("bb",(Nullable!int).init)` i.e. in the null state)
why nullables don't automatically check for null when comparing
for equality idk.
you can make this work by defining your own opEquals that
explicitly checks for nulls.
