| #### 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 |