Operating overloading on custom type is broken

[shiinamiyuki]

The best working attemp is

#[derive(Clone, Copy, Debug, Value, PartialEq)]
#[repr(C)]
#[value_new(pub)]
pub struct CustomAdd {
    i: f32,
}
impl AddExpr<CustomAddExpr> for CustomAddExpr {
    type Output = Expr<CustomAdd>;
    #[tracked]
    fn add(self, rhs: CustomAddExpr) -> Expr<CustomAdd> {
        let rhs = rhs.as_expr_from_proxy();
        let self_ = self.self_.var();
        *self_.i += rhs.i;
        **self_
    }
}
impl AddMaybeExpr<CustomAddExpr, luisa_compute::lang::types::ExprType> for Expr<CustomAdd> {
    type Output = Expr<CustomAdd>;
    fn __add(self, rhs: CustomAddExpr) -> Self::Output {
        self.add(rhs)
    }
}
fn custom_add(a: Expr<CustomAdd>, b: Expr<CustomAdd>) -> Expr<CustomAdd> {
    track!(a + *b)
}