Method try_visit_mut_post

src/expr/src/visit.rs:311–338

(&mut self, f: &mut F)

    #[allow(clippy::as_conversions)]
    fn try_visit_mut_post<F, E>(&mut self, f: &mut F) -> Result<(), E>
    where
        F: FnMut(&mut Self) -> Result<(), E>,
    {
        // This code uses `unsafe`. The core safety argument is that:
        //
        // - `children_mut()` produces disjoint children
        // - no aliasing means each `Enter` is processed separately, and we `Leave` each node exactly once
        //
        // Put another way, our `stack` mirrors the function call stack, which allows multiple `&mut` refs at once,
        // since only one stack frame can be active at a time.

        use VisitMutAction::*;
        let mut stack = vec![Enter(self as *mut T)];
        while let Some(action) = stack.pop() {
            match action {
                Enter(ptr) => {
                    stack.push(Leave(ptr));
                    let elt = unsafe { &mut *ptr };
                    // Push children in reverse so they pop (and are visited) left-to-right.
                    stack.extend(elt.children_mut().rev().map(|child| Enter(child as *mut T)));
                }
                Leave(ptr) => f(unsafe { &mut *ptr })?,
            }
        }

        Ok(())
    }

    fn visit_pre<F>(&self, f: &mut F)
    where