Compile or improve error message for static Self #119936
Description
Code
impl MyStruct {
fn instance() -> &'static Self {
static MYSTRUCT: OnceLock<Self> = OnceLock::new();
MYSTRUCT.get_or_init(|| Self { msg: "Hello world!" })
}
}Current output
Compiling playground v0.0.1 (/playground)
error[E0401]: can't use generic parameters from outer item
--> src/main.rs:10:35
|
8 | impl MyStruct {
| ---- `Self` type implicitly declared here, by this `impl`
9 | fn instance() -> &'static Self {
10 | static MYSTRUCT: OnceLock<Self> = OnceLock::new();
| ^^^^
| |
| use of generic parameter from outer item
| refer to the type directly here insteadDesired output
It should either compile, or have a different messageRationale and extra context
The message says use of generic parameter from outer item - refer to the type directly here instead
This makes you believe that Self is a generic type, but it isn't. MyStruct can also be known at compile time at doesn't have generics attached to it, so maybe it could even compile.
Other cases
Changing the `Self` to `MyStruct`, which is the same thing, will make the code compile.Rust Version
$ rustc --version --verbose
rustc 1.75.0 (82e1608df 2023-12-21)
binary: rustc
commit-hash: 82e1608dfa6e0b5569232559e3d385fea5a93112
commit-date: 2023-12-21
host: x86_64-unknown-linux-musl
release: 1.75.0
LLVM version: 17.0.6Anything else?
No response
Activity
clubby789 commentedon Jan 13, 2024
Looks like essentially the same issue as #109596
Auto merge of rust-lang#119939 - clubby789:static-const-generic-note,…
Rollup merge of rust-lang#119939 - clubby789:static-const-generic-not…
Rollup merge of rust-lang#119939 - clubby789:static-const-generic-not…
Rollup merge of rust-lang#119939 - clubby789:static-const-generic-not…
Unrolled build for rust-lang#119939