use std::mem;

/// Simple inefficient datastructure with guaranteed drop order
#[derive(Debug)]
pub enum Stack<T> {
	Cons(Box<(T, Stack<T>)>),
	Empty,
}

impl<T> Default for Stack<T> {
	fn default() -> Self {
		Self::Empty
	}
}

impl<T> Stack<T> {
	pub fn new() -> Self {
		Self::Empty
	}

	pub fn push(&mut self, value: T) {
		let tmp = mem::take(self);
		*self = Stack::Cons(Box::new((value, tmp)));
	}
}