Method try_borrow_mut

src/sharedref.rs:167–179

Mutably borrows the wrapped value, returning an error if the value is currently borrowed.

(&self)

    /// Mutably borrows the wrapped value, returning an error if the value
    /// is currently borrowed.
    pub fn try_borrow_mut(&self) -> result::Result<RefMut<'a, T>, BorrowMutError> {
        // the value may be immutably borrowed through UnsafePyLeaked
        if self.state.current_borrow_count(self.py) > 0 {
            // propagate borrow-by-leaked state to data to get BorrowMutError
            let _dummy = self.data.borrow();
            self.data.try_borrow_mut()?;
            unreachable!("BorrowMutError must be returned");
        }

        let data_ref = self.data.try_borrow_mut()?;
        self.state.increment_generation(self.py);
        Ok(data_ref)
    }

    /// Creates an immutable reference which is not bound to lifetime.
    ///