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    <p>You cannot override them separately, you must override both at once:</p> <pre><code>struct Interface1 { virtual void Name() = 0; }; struct Interface2 { virtual void Name() = 0; }; struct RealClass : Interface1, Interface2 { virtual void Name(); }; // and move it out of the class definition just like any other method: void RealClass::Name() { printf("Interface1 OK?\n"); printf("Interface2 OK?\n"); } </code></pre> <p>You can simulate individual overriding with intermediate base classes:</p> <pre><code>struct RealClass1 : Interface1 { virtual void Name() { printf("Interface1 OK?\n"); } }; struct RealClass2 : Interface2 { virtual void Name() { printf("Interface2 OK?\n"); } }; struct RealClass : RealClass1, RealClass2 { virtual void Name() { // you must still decide what to do here, which is likely calling both: RealClass1::Name(); RealClass2::Name(); // or doing something else entirely // but note: this is the function which will be called in all cases // of *virtual dispatch* (for instances of this class), as it is the // final overrider, the above separate definition is merely // code-organization convenience } }; </code></pre> <p>Additionally, you're using reinterpret_cast incorrectly, you should have:</p> <pre><code>int main() { RealClass rc; // no need for dynamic allocation in this example Interface1&amp; one = rc; one.Name(); Interface2&amp; two = dynamic_cast&lt;Interface2&amp;&gt;(one); two.Name(); return 0; } </code></pre> <p>And here's a rewrite with <a href="http://en.wikipedia.org/wiki/Curiously_recurring_template_pattern" rel="nofollow noreferrer">CRTP</a> that might be what you want (or not):</p> <pre><code>template&lt;class Derived&gt; struct RealClass1 : Interface1 { #define self (*static_cast&lt;Derived*&gt;(this)) virtual void Name() { printf("Interface1 for %s\n", self.name.c_str()); } #undef self }; template&lt;class Derived&gt; struct RealClass2 : Interface2 { #define self (*static_cast&lt;Derived*&gt;(this)) virtual void Name() { printf("Interface2 for %s\n", self.name.c_str()); } #undef self }; struct RealClass : RealClass1&lt;RealClass&gt;, RealClass2&lt;RealClass&gt; { std::string name; RealClass() : name("real code would have members you need to access") {} }; </code></pre> <p>But note that here you cannot call Name on a RealClass now (with virtual dispatch, e.g. <code>rc.Name()</code>), you must first select a base. The self macro is an easy way to clean up CRTP casts (usually member access is much more common in the CRTP base), but it can be <a href="http://bitbucket.org/kniht/scraps/src/tip/cpp/crtp.hpp" rel="nofollow noreferrer">improved</a>. There's a brief discussion of virtual dispatch in one of my <a href="https://stackoverflow.com/questions/1963926/when-is-a-v-table-created-in-c/1963977#1963977">other answers</a>, but surely a better one around if someone has a link.</p>
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    1. POInherit interfaces which share a method name
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    1. COYour intermediate base classes don't appear to do anything. You can still call `Interface1::Name` just the same as `RealClass1::Name`.
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    2. CO… I mean, you could, if it were implemented as for RealClass1.
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    3. COYou cannot call `rc.Interface1::Name()`, that is a pure virtual function without implementation.
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