Method dec

datafusion/expr/src/logical_plan/plan.rs:4721–4728

Decrements the counter by 1, if any, returning true if it hits zero

(&mut self)

        }
        // Decrements the counter by 1, if any, returning true if it hits zero
        fn dec(&mut self) -> bool {
            if Some(0) == self.val {
                true
            } else {
                self.val = self.val.take().map(|i| i - 1);
                false
            }
        }
    }

    #[derive(Debug, Default)]