commit cf9e29e0f686faeb22fc2e1201339ab53b29305c
author bors[bot] <26634292+bors[bot]@users.noreply.github.com> Mon Mar 23 20:46:13 2020 +0000
committer GitHub <noreply@github.com> Mon Mar 23 20:46:13 2020 +0000
tree 96ff168e4e907053f5f1988289c7202570635bb9
parent 246660c52874f20a2a633867c9b786f91b8a1004
parent 8a6f5e3cc97f3762ac9841ce870edcee82df1dba

Merge #23

23: Add a deref-removing impl for TextSized r=CAD97 a=CAD97

Notably, given `s: &SmolStr`, `TextSize::of(s)` does not work, where `TextUnit::of_str(s)` did, because the concrete type could be deref-coerced to. (It's probably a limitation of the language that deref coersion does not apply here, but it's one we have to live with.)

So we provide a blanket impl for any type that derefs (directly) to `str`.

Alternatively, we can provide a deeper blanket impl that derefs any number of references recursively [[playground](https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=008b5e0c2edd332b34b3efa42ce2a40a)]:

```rust
impl<D> TextSized for &'_ D
where
    D: Deref,
    for<'a> &'a D::Target: TextSized,
{
    #[inline]
    fn text_size(self) -> TextSize {
        self.deref().text_size()
    }
}
```

This is "only" at the cost of a little extra impl complexity.

Co-authored-by: CAD97 <cad97@cad97.com>