Is stack-only variable possible in C++?

Currently I want to make wrapper accessor class in multithreaded environment. The purpose of the class is simple - Grab a lock on its construction and release a lock on its destruction. Other than that, it's identical to a normal pointer. Moreover, I 开发者_如何学Cwant to prevent it from being created on heap area to ensure that the lock will be released eventually.

The inverse is fairly easy (private constructor with factory method), but I don't know that a stack-only variable is possible. Is there anyway?

Well, what about you overload operator new for your class and delcare it private?

I don't understand the problem? Any variable defined within the scope of a function is stack-only.

class Lock {
public:
    Lock() {
        performLock();
    }

    ~Lock() {
        performUnlock();
    }
}

void foo() {
    // ... Code
    Lock onStackOnly;
    // ... Code that is locked
}


void foo() {
    // ... Code
    {
        Lock onStackOnly;
        // ... Code that is locked
    }

    // This code is unlocked.
}