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POtypedef with CRTP doesn't work when inheritance is used
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  1. POtypedef with CRTP doesn't work when inheritance is used
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    copied!<p>Is there any ways to define a type with a same name for classes in inheritance relationship by using CTRP? I tried the following code but got <code>error: member 'ptr_t' found in multiple base classes of different types</code> from <code>clang++</code>.</p> <pre><code>#include &lt;iostream&gt; #include &lt;tr1/memory&gt; template &lt;typename T&gt; class Pointable { public: // define a type `ptr_t` in the class `T` publicly typedef std::tr1::shared_ptr&lt;T&gt; ptr_t; }; class Parent : public Pointable&lt;Parent&gt; { public: Parent() { std::cout &lt;&lt; "Parent created" &lt;&lt; std::endl; } ~Parent() { std::cout &lt;&lt; "Parent deleted" &lt;&lt; std::endl; } }; class Child : public Parent, public Pointable&lt;Child&gt; { public: Child() { std::cout &lt;&lt; "Child created" &lt;&lt; std::endl; } ~Child() { std::cout &lt;&lt; "Child deleted" &lt;&lt; std::endl; } }; int main(int argc, char** argv) { Child::ptr_t child_ptr(new Child()); Parent::ptr_t parent_ptr(new Parent()); return 0; } </code></pre> <p>Of course, the following one is OK (but it's redundant and go against the DRY principle).</p> <pre><code>class Parent { public: typedef std::tr1::shared_ptr&lt;Parent&gt; ptr_t; Parent() { std::cout &lt;&lt; "Parent created" &lt;&lt; std::endl; } ~Parent() { std::cout &lt;&lt; "Parent deleted" &lt;&lt; std::endl; } }; class Child : public Parent { public: typedef std::tr1::shared_ptr&lt;Child&gt; ptr_t; Child() { std::cout &lt;&lt; "Child created" &lt;&lt; std::endl; } ~Child() { std::cout &lt;&lt; "Child deleted" &lt;&lt; std::endl; } }; </code></pre> <p>If there is no ways to achieve this behavior by using CRTP, why that is prohibited?</p>
 

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