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copied!<blockquote> <p>Is there a way to call member function of a class without the class object on left hand side?</p> <p>...</p> <p>so, is there a way (or hack) to call <code>D::foo</code> with class object passed to it as function argument instead of using <code>.</code> or <code>-></code> or <code>.*</code> or <code>->*</code> operators on class object?</p> </blockquote> <p>In short, no. You cannot call a non-<code>static</code> class member function without somehow specifying the object on the left side of the call. If the class (for static functions) or the object (for non-static) is not specified, the compiler has no way of knowing which function you are trying to call. It's outside the current scope because it's inside a class or object. There are ways to "hack" code so you can write it to look like <code>main()</code> in your example. Some of the other answers give examples of just these kinds of hacks.</p> <p>------------Using static functions-----------------</p> <p>A function within a class <em>can</em> be called outside the class without specifying a class object. The way to do it is to create a <code>typedef</code> for a function pointer with a signature that matches the class function's, then creating such a pointer and assigning it the address of the class function. That function can then be called without needing to specify the class or an object on the left side.</p> <p>The function <strong>must</strong> be <code>static</code>. ISO C++ does not allow taking the address of a bound member function to form a pointer to that function, i.e. you cannot create a pointer to a non-<code>static</code> member function from a class object. You may be able to find some non-ISO standard compliant compilers, but I don't have any guidance on that for you.</p> <p>The parameter <code>this</code> to non-<code>static</code> class member functions is an implied parameter, and is always an implied parameter. You cannot manually specify it, but you <em>can</em> emulate it by passing a pointer to an object of the class.</p> <p>So, for your code example:</p> <ul> <li><code>void D::foo(int)</code> should be <code>static</code> and have an added <code>D*</code> parameter: <code>class D { static void D::foo(D*, int); };</code>.</li> <li><code>typedef void (D::* Func)(int);</code> should be changed to accommodate the previous change and remove <code>D::</code>: <code>typedef void (*Func)(D*, int);</code></li> </ul>

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