rust type_error ai_generated true

error[E0412]: cannot find type `X` in this scope

ID: rust/e0412-type-not-found

Also available as: JSON · Markdown
95%Fix Rate
95%Confidence
50Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1 active — — —

Root Cause

Type not in scope. Missing use statement, typo, or missing dependency.

generic

Workarounds

  1. 95% success Add the correct use statement to import the type 
    use std::collections::HashMap;

    Sources: https://doc.rust-lang.org/error_codes/E0412.html

  2. 90% success Check Cargo.toml for missing dependency if the type is from an external crate 
    Check Cargo.toml for missing dependency if the type is from an external crate

    Sources: https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html

  3. 88% success Check for typos in the type name — Rust is case-sensitive 
    Check for typos in the type name — Rust is case-sensitive

    Sources: https://doc.rust-lang.org/reference/items.html

Dead Ends

Common approaches that don't work:

  1. Define a type alias 65% fail

    If the type exists elsewhere, alias just adds confusion

  2. Use dyn Any instead 85% fail

    Loses all type safety and requires downcasting

Error Chain

Frequently confused with: