Errors when comparing types

[nventuro]

Aim

I'm running into multiple issues related to type inference. This is one of them, but I'm not entirely sure how to title this report because I don't really know what might be the underlying issue. I produced a small exaple that triggers it instead.

Ultimately this errors out with error: Types in a binary operation should match, but found T and T, which just seems wrong.

Expected Behavior

Forgive the boiler-plate, hopefully it won't be too bad. It's just some standard utils for dealing with Fields and arrays as is done in the kernel circuits.

trait FromField {
    fn from_field(field: Field) -> Self;
}

impl FromField for Field {
    fn from_field(value: Field) -> Self {
        value
    }
}

trait Deserialize<N> {
    fn deserialize(fields: [Field; N]) -> Self;
}

global AZTEC_ADDRESS_LENGTH = 1;

struct AztecAddress {
    inner : Field
}

impl FromField for AztecAddress {
    fn from_field(value: Field) -> Self {
        Self { inner: value }
    }
}

impl Deserialize<AZTEC_ADDRESS_LENGTH> for AztecAddress {
    fn deserialize(fields: [Field; AZTEC_ADDRESS_LENGTH]) -> Self {
        AztecAddress::from_field(fields[0])
    }
}

// Custom code

struct MyStruct<T> {
    a: T
}

impl<T> Deserialize<1> for MyStruct<T> {
    fn deserialize(fields: [Field; 1]) -> Self where T: FromField {
        Self{ a: FromField::from_field(fields[0]) }
    }
}

fn main() {
    let fields = [5; 1];
    let foo = MyStruct::deserialize(fields); // Note I don't specify T here (the type of `foo.a`)

    let bar = AztecAddress { inner: 5 };

    // Here `T` is apparently inferred to be `AztecAddress`, presumably because of the comparison.
    assert(foo.a == bar);
}

This errors out with:

error: Types in a binary operation should match, but found AztecAddress and AztecAddress
   ┌─ /home/nventuro/type_error/src/main.nr:49:12
   │
49 │     assert(foo.a == bar);
   │            ------------

which feels a bit non-sensical.

Bug

Honestly I'm not sure if the issue is my code, the error message or the compiler, but something does seem off here.

Installation Method

Compiled from source

Nargo Version

nargo version = 0.25.0 noirc version = 0.25.0+7deceac68414a6c24f2c4f9ecdd36ad6ac9752e3 (git version hash: 7deceac68414a6c24f2c4f9ecdd36ad6ac9752e3, is dirty: false)