pub fn dereference_mut(&mut self) -> &mut Self {
        // TODO: probably more ZTS work is needed here
        if self.is_reference() {
            #[allow(clippy::unwrap_used)]
            return self.reference_mut().unwrap();
        }
        if self.is_indirect() {
            #[allow(clippy::unwrap_used)]
            return self.indirect_mut().unwrap();
        }
        self
    }
Dereference the zval mutable, if it is a reference.

# Panics

Panics if a mutable reference to the zval is not possible.
src/types/zval.rs