rust ownership_error ai_generated true

error[E0507]: cannot move out of borrowed content

ID: rust/e0507-move-out-of-borrow

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88%Fix Rate
90%Confidence
50Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1 active — — —

Root Cause

Trying to take ownership of a value behind a reference. Core ownership rule violation.

generic

Workarounds

  1. 90% success Clone the value if you need a separate copy: value.clone() 
    value.clone()

    Sources: https://doc.rust-lang.org/std/clone/trait.Clone.html

  2. 88% success Use .as_ref() or pattern matching with ref to avoid moving 
    match &my_option { Some(ref val) => { ... } }

    Sources: https://doc.rust-lang.org/error_codes/E0507.html

  3. 85% success Consider restructuring to pass by reference instead of by value 
    // Pass by reference instead of by value:
fn process(item: &Item) -> String { // borrows, doesn't consume
    item.name.clone()
}

// Or if you need the value, take ownership of the parameter:
fn consume(item: Item) -> String { // takes ownership
    item.name
}

    Sources: https://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html

Dead Ends

Common approaches that don't work:

  1. Use unsafe to bypass the borrow checker 95% fail

    Never use unsafe to work around ownership — it will cause UB

  2. Make everything Copy 70% fail

    Not all types can be Copy (String, Vec, etc.)

Error Chain

Leads to: