Question

I need to call a const function from a non-const object. See example

struct IProcess {    virtual bool doSomeWork() const = 0L; }; class Foo : public IProcess {       virtual bool doSomeWork() const {     ...   } };  class Bar { public:    const IProcess& getProcess() const {return ...;}    IProcess& getProcess() {return ...;}     void doOtherWork {     getProcess().doSomeWork();           } }; 

Calling

getProcess().doSomeWork(); 

will always results in a call to

IProcess& getProcess() 

Is there another way to call

const IProcess& getProcess() const  

from a non constant member function? I have so far used

const_cast<const Bar*>(this)->getProcess().doSomeWork(); 

which does the trick but seems overly complicated.

---

Edit: I should mention that code is being refactored and eventually only one function will remain.

const IProcess& getProcess() const  

However, currently there is a side effect and the const call may return a different instance of IProcess some of the time.

Please keep on topic.

Answer 1

Avoid the cast: assign this to a const Bar * or whatever and use that to call getProcess().

There are some pedantic reasons to do that, but it also makes it more obvious what you are doing without forcing the compiler to do something potentially unsafe. Granted, you may never hit those cases, but you might as well write something that doesn’t use a cast in this case.