vec.cpp

// Branch factor, power of two.
static constexpr SizeP2 RADIX = SIZEP2_32;

enum class NodeKind {
	LEAF = 1, BRANCH
};

class Node : public RefCounted {
public:
	constexpr Node(NodeKind kind) noexcept : kind_(kind) {}

private:
	NodeKind kind_;
};

class Leaf final : public Node {
public:
	Leaf() : Node(NodeKind::LEAF) {}

	~Leaf() = default;

	T values[std::size_t(RADIX)];
};

class Branch final : public Node {
public:
	Branch() : Node(NodeKind::BRANCH) {}

	~Branch() = default;

	Rc<const Node> children[std::size_t(RADIX)] = {0};
};

class Either final : public Node {
	~Either() noexcept {
		switch(kind_) {
		case NodeKind::LEAF:
			static_cast<Leaf*>(this)->~Leaf();
			break;
		case NodeKind::BRANCH:
			static_cast<Branch*>(this)->~Branch();
			break;
		}
	}
};