Specific impls of generic struct does not work / is not implemented

[emilyaherbert]

This fails to compile:

script;

struct DoubleIdentity<T, F> {
  first: T,
  second: F
}

impl DoubleIdentity<bool, bool> {
  fn and(self) -> bool {
    self.first && self.second
  }
}

fn main() -> bool {
  let foo = DoubleIdentity {
    first: true,
    second: true
  };
  foo.and()
}

Giving:

Probably related to #814. This should behave like: https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=4209730e624308ce86c626fb69e8e1f4

[emilyaherbert]

Closed by #913