Nullable field optimization does the Wrong Thing when faced with associated types

[arielb1]

STR

use std::mem;
trait Mirror { type Image; }
impl<T> Mirror for T { type Image = T; }
struct S1<T>(<T as Mirror>::Image);
struct S2<T>(T);

fn main() {
    println!("with: {}", mem::size_of::<Option<S1<&u8>>>());
    println!("without: {}", mem::size_of::<Option<S2<&u8>>>());
}

Expected Result

Nullable field optimization should be triggered in both cases

Result

with: 8
without: 16

[jonas-schievink]

I think you swapped the results by accident

[eefriedman]

It looks like the issue is just a couple missing calls to monomorphize::normalize_associated_type; I'm working on a fix.

[arielb1]

I will fix this with my ADTDef patch (coming real soon now) - I should have made that clearer.