Unexpected Type Mismatch

[sharp badger]

I have a struct that uses std ArrayListUnmanaged like so:

const Bar = struct {
  cols: ds.ArrayListUnmanaged(*Foo)

  fn init() @This() {
    return @This() {.cols = ds.ArrayListUnmanaged(*Foo).init()};
  }
}

// ds.ArrayListUnmanaged(*Foo).init() is simply:
fn init() @This() {
  return @This() {.list = std.ArrayListUnmanaged(T){}};
 }

calling Bar.init() results in an error:
expected type ds.ArrayListUnmanaged(*foo.Foo), found ds.ArrayListUnmanaged(*foo.Foo), which doesn't really make sense.

However, aliasing ds.ArrayListUnmanaged(*Foo) resolves the issue (i.e. const Thing = ds.ArrayListUnmanaged(*Foo)).

Any ideas?

[tribal lichen]

ds.ArrayListUnmanaged is just a wrapper around std.ArrayListUnmanaged?

[sharp badger]

Exactly

[tribal lichen]

hmm

while i think about this i'll suggest some style things: in Bar you can probably make init return Bar instead of @This(), while in ds.ArrayListUnmanaged you could use const Self = @This();. you only really need @This() for generics: https://zig.news/kristoff/dont-self-simple-structs-fj8

and in both you can use .{ fields } instead of @This() { fields } -- letting zig infer the struct type since it knows the return type

[sharp badger]

that makes sense. Will definitely refactor. Thanks.

[tribal lichen]

are Bar, Foo, and ds.ArrayListUnmanaged in three separate files?

[sharp badger]

Yeah, that's correct

[tribal lichen]

my instinct is saying that somehow "the same type imported in two different places" does not end up actually being the same type, except i don't think that should actually happen in zig

is your full project pushed anywhere i could take a look?

[sharp badger]

yeah, i'm really surprised by the error. It's not hosted anywhere atm. This also doesn't happen with wrappers around std.ArrayList.

[cloud gyro]

you're missing a comma after the field definition in Bar