| #### Note: this error code is no longer emitted by the compiler |
| |
| This is because it was too specific to the `optimize` attribute. |
| Similar diagnostics occur for other attributes too. |
| The example here will now emit `E0539` |
| |
| The `optimize` attribute was malformed. |
| |
| Erroneous code example: |
| |
| ```compile_fail,E0539 |
| #![feature(optimize_attribute)] |
| |
| #[optimize(something)] // error: invalid argument |
| pub fn something() {} |
| ``` |
| |
| The `#[optimize]` attribute should be used as follows: |
| |
| - `#[optimize(size)]` -- instructs the optimization pipeline to generate code |
| that's smaller rather than faster |
| |
| - `#[optimize(speed)]` -- instructs the optimization pipeline to generate code |
| that's faster rather than smaller |
| |
| For example: |
| |
| ``` |
| #![feature(optimize_attribute)] |
| |
| #[optimize(size)] |
| pub fn something() {} |
| ``` |
| |
| See [RFC 2412] for more details. |
| |
| [RFC 2412]: https://rust-lang.github.io/rfcs/2412-optimize-attr.html |
