问delete操作符在什么上下文中抛出错误？

EN

class LinkedList {
public:
    LinkedList() : head(nullptr) {}
    ~LinkedList() { clear(); }

    void push_front() {
        head = createNode(head);
    }

    void clear() {
        Node* current_node = head;
        while (current_node != nullptr) {
            Node* next_node = current_node->next; // buffer
            deleteNode(current_node);
            current_node = next_node;
        }
    }

private:    
    struct Node {
        Node(Node* next)
            : next(next) {}
        Node* next;
    };
    Node* head;
    Node* createNode(Node* next) {
        return new Node(next);
    }
    void deleteNode(Node*& toDelete) {
        delete toDelete; // ***VS 2015 puts breakpoint here***
        toDelete = nullptr;
    }
};

int main() {
    auto A = LinkedList();
    A.push_front();
    A.clear();
    return 0;
}