* James Munns Sorry for the ping and only if you know it up front, otherwise I'll test. If I do:

```rust
const FOO: Foo = Foo:new(); // `Foo`'s initial layout is "all 0s"
unsafe { ptr.write(&FOO) }
```

rustc will be smart enough - _under all compiler opt settings_ - to optimize `ptr.write(&FOO)` with `memset(..., 0)`, right? (This is an evolution of our `Pool` conversation from yesterday and in a way related to the `SliceVec` discussion which had happened yesterday)