Function compare

src/ifcgeom/taxonomy.cpp:26–44

	template <typename T>
	bool compare(const eigen_base<T>& t, const eigen_base<T>& u) {
		if (t.components_ == nullptr && u.components_ == nullptr) {
			return false;
		}
		else if (t.components_ == nullptr && u.components_ != nullptr) {
			return true;
		}
		else if (t.components_ != nullptr && u.components_ == nullptr) {
			return false;
		}

		auto t_begin = t.components_->data();
		auto t_end = t.components_->data() + t.components_->size();

		auto u_begin = u.components_->data();
		auto u_end = u.components_->data() + u.components_->size();

		return std::lexicographical_compare(t_begin, t_end, u_begin, u_end);
	}

	bool compare(const line& a, const line& b) {
		return compare(*a.matrix, *b.matrix);