6b62f37402
Currently a `{D,Subd}iagnosticMessage` can be created from any type that
impls `Into<String>`. That includes `&str`, `String`, and `Cow<'static,
str>`, which are reasonable. It also includes `&String`, which is pretty
weird, and results in many places making unnecessary allocations for
patterns like this:
```
self.fatal(&format!(...))
```
This creates a string with `format!`, takes a reference, passes the
reference to `fatal`, which does an `into()`, which clones the
reference, doing a second allocation. Two allocations for a single
string, bleh.
This commit changes the `From` impls so that you can only create a
`{D,Subd}iagnosticMessage` from `&str`, `String`, or `Cow<'static,
str>`. This requires changing all the places that currently create one
from a `&String`. Most of these are of the `&format!(...)` form
described above; each one removes an unnecessary static `&`, plus an
allocation when executed. There are also a few places where the existing
use of `&String` was more reasonable; these now just use `clone()` at
the call site.
As well as making the code nicer and more efficient, this is a step
towards possibly using `Cow<'static, str>` in
`{D,Subd}iagnosticMessage::{Str,Eager}`. That would require changing
the `From<&'a str>` impls to `From<&'static str>`, which is doable, but
I'm not yet sure if it's worthwhile.
|
||
|---|---|---|
| .. | ||
| clean | ||
| doctest | ||
| formats | ||
| html | ||
| json | ||
| passes | ||
| theme | ||
| askama.toml | ||
| Cargo.toml | ||
| config.rs | ||
| core.rs | ||
| docfs.rs | ||
| doctest.rs | ||
| error.rs | ||
| externalfiles.rs | ||
| fold.rs | ||
| lib.rs | ||
| lint.rs | ||
| markdown.rs | ||
| README.md | ||
| scrape_examples.rs | ||
| theme.rs | ||
| visit.rs | ||
| visit_ast.rs | ||
| visit_lib.rs | ||
For more information about how librustdoc works, see the rustc dev guide.