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copied!<p>The error is most likely from the use of the function pointer to point to member functions. There is a considerable difference between functions that are in classes and just normal functions. You are assigning a class function to a normal function pointer. The difference comes in when you consider that all member functions take a hidden <code>this</code> pointer as their first argument.</p> <p>Either change the functions to be outside of the class (or instead use static functions if the functions do not need any of the class's variables, bases or the <code>this</code> pointer) or change the function pointer to a class member function pointer. A pointer to a MyClass function that takes a string will look like this.</p> <pre><code>void (MyClass::*fptr)(std::string str); </code></pre> <p>Because the class function pointer requires a hidden <code>this</code> pointer the call of the function pointer changes also. To call the function pointed to by fptr you can use the <code>->*</code> or <code>.*</code> c++ operators. So to call it using the <code>this</code> pointer of MyClass you can do this:</p> <pre><code>std::string aString; (this->*fptr)(aString); </code></pre> <p>I'm not entirely sure but it maybe possible to do what you hope to do with virtual functions instead? This can be achieved by having two separate classes and a pointer to an instance of one of the two. Both classes derive from a class that has a pure virtual function that is the same as the function you are assigning here. This is a cleaner solution than using function pointers. I would look into this as you may find it useful if your looking for dynamic behavior using function pointers.</p> <p>This is a good tutorial on the basics of function pointers:</p> <p><a href="http://www.learncpp.com/cpp-tutorial/78-function-pointers/" rel="nofollow">http://www.learncpp.com/cpp-tutorial/78-function-pointers/</a></p>

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