Repository navigation
rustc confuses missing types with missing type parameters #139999
Description
Code
pub fn do_stuff() -> Option<ForgotToImport> {
None
}Current output
error[E0412]: cannot find type `ForgotToImport` in this scope
--> src/lib.rs:1:29
|
1 | pub fn do_stuff() -> Option<ForgotToImport> {
| ^^^^^^^^^^^^^^ not found in this scope
|
help: you might be missing a type parameter
|
1 | pub fn do_stuff<ForgotToImport>() -> Option<ForgotToImport> {
| ++++++++++++++++Desired output
error[E0412]: cannot find type `ForgotToImport` in this scope
--> src/lib.rs:1:29
|
1 | pub fn do_stuff() -> Option<ForgotToImport> {
| ^^^^^^^^^^^^^^ not found in this scopeRationale and extra context
Type parameters are rarely this long, so rustc's guess seems like a poor fit. Could rustc treat longer names as unlikely to be type parameters?
Another option would be to skip this suggestion if the type name is CamelCase.
Other cases
Rust Version
$ rustc --version --verbose
rustc 1.86.0 (05f9846f8 2025-03-31)
binary: rustc
commit-hash: 05f9846f893b09a1be1fc8560e33fc3c815cfecb
commit-date: 2025-03-31
host: x86_64-unknown-linux-gnu
release: 1.86.0
LLVM version: 19.1.7Anything else?
No response
Activity
[-]rustc confuses missing types with type parameters[/-][+]rustc confuses missing types with missing type parameters[/+]Kivooeo commentedon Apr 19, 2025
Hi, would love to take this one, almost finished writing implementation, and will add tests and so on tomorrow and publish it in PR
fix for rust-lang#139999
fix for rust-lang#139999
fix for rust-lang#139999
fix for rust-lang#139999