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    <p>The code you posted will not compile because the compiler has no Idea what <code>derived</code> class is while compiling the code for <code>class Base</code>. the <code>this</code> pointer is a pointer that is implicitly passed to every non static member function of a class its how that function can access member attributes of the it's instance. In a <code>Base</code> class member function <code>this</code> has type <code>Base *</code> In a <code>const</code> member function it will have the type <code>const Base *</code>.</p> <p>Also the <code>this</code> is a non l-value that means you can not assign a value to it.</p> <p>The following is from the C++ standard about the this pointer:</p> <blockquote> <p>9.3.2 The this pointer</p> <p>In the body of a non-static (9.3) member function, the keyword this is a prvalue expression whose value is the address of the object for which the function is called. The type of this in a member function of a class X is X*. If the member function is declared const, the type of this is const X*, if the member function is declared volatile, the type of this is volatile X*, and if the member function is declared const volatile, the type of this is const volatile X*.</p> </blockquote> <p>Now as for doing what you want to do in your question the following compiles</p> <pre><code>#include &lt;iostream&gt; class Base { public: void get(); }; class derived: public Base { public: void put() { std::cout &lt;&lt; "This is a bad idea" &lt;&lt; std::endl; } }; void Base::get() { //compiler knows what dervied class is static_cast&lt;derived *&gt;(this)-&gt;put(); } int main() { derived d; d.get(); return 0; } </code></pre> <p>output is : <code>This is a bad idea</code></p> <p>I recommend using virtual functions or templates to get the desired behaviour.</p>
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