rust trait-system ai_generated true

error[E0277]: the trait bound `MyType: Send` is not satisfied

ID: rust/e0277-trait-not-implemented

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92%Fix Rate
94%Confidence
50Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1 active — — —

Root Cause

A type doesn't implement a required trait, commonly Send/Sync for async or Display for formatting.

generic

Workarounds

  1. 85% success Implement the required trait: impl Send for MyType if the type is actually safe to send 
    Only if all fields are Send — verify before implementing
  2. 90% success Wrap non-Send types in Arc<Mutex<T>> for shared ownership across threads 
    Arc<Mutex<T>> is Send + Sync if T is Send

    Sources: https://doc.rust-lang.org/book/ch16-03-shared-state.html

Dead Ends

Common approaches that don't work:

  1. Using unsafe impl Send for MyType {} 95% fail

    Lying to the compiler about thread safety causes data races

  2. Removing the async requirement 60% fail

    May require major architectural changes just to avoid a trait bound

Error Chain

Frequently confused with: