Defining volatile class object

问题

Can the volatile be used for class objects? Like:

volatile Myclass className;

The problem is that it doesn't compile, everywhere when some method is invoked, the error says: error C2662: 'function' : cannot convert 'this' pointer from 'volatile MyClass' to 'MyCLass &'

What is the problem here and how to solve it?

EDIT:

class Queue {
            private:
                struct Data *data;
                int amount;
                int size;
            public:
                Queue ();
                ~Queue ();
                bool volatile push(struct Data element);
                bool volatile pop(struct Data *element);
                void volatile cleanUp();
            };
    .....
    volatile Queue dataIn;

        .....

    EnterCriticalSection(&CriticalSection);
    dataIn.push(element);
    LeaveCriticalSection(&CriticalSection);

回答1:

Yes, you can, but then you can only call member functions that are declared volatile (just like the const keyword). For example:

 struct foo {
    void a() volatile;
    void b();
 };

 volatile foo f;
 f.a(); // ok
 f.b(); // not ok

Edit based on your code:

bool volatile push(struct Data element);

declares a non-volatile member function that returns a bool volatile (= volatile bool). You want

bool push(struct Data element) volatile;

回答2:

I think he meant to say

            bool push(struct Data element) volatile;

instead of

            bool volatile push(struct Data element);

Also have a look here http://www.devx.com/tips/Tip/13671

回答3:

In C++ grammar, "volatile" and "const" are called "CV modifiers". That means "volatile" works in exact the same way as "const" from syntactic point of view. You can replace all "volatile" with "const" then you can understand why your code compiles or not.

回答4:

Yep. We can use. Please see the modified code. I hope it should work now.

class Queue {
            private:
                struct Data *data;
                int amount;
                int size;
            public:
                Queue ();
                ~Queue ();
                bool push(struct Data element) volatile;
                bool pop(struct Data *element) volatile;
                void cleanUp() volatile;
            };
.....
volatile Queue dataIn;

    .....

EnterCriticalSection(&CriticalSection);
dataIn.push(element);
LeaveCriticalSection(&CriticalSection);

来源：https://stackoverflow.com/questions/3078237/defining-volatile-class-object

标签

c++

volatile