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POWhere should the pure virtual destructor be declared?
 

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  1. POWhere should the pure virtual destructor be declared?
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    <p>EDIT: Apparently the question is not clearly formulated enough. The issue I am having is that when the destructor is defined in the header it gets added into multiple .obj files and the linker complains. The actual question is:</p> <p>When I add the destructor to a CPP file in a DLL project and use the dll with dynamic loading and the interface header file, does the base destructor still get called to prevent leaking memory?</p> <p>I am using MSVC 10.0 and have a DLL project that implements an interface. The interface is an abstract (pure virtual) base class. The idea is that the header is used with dynamic loading of the library. Therefore, I have used a pure virtual destructor to make sure the destructor in the base class gets called. Here is sample code to explain this:</p> <pre><code>//ISplitter.h #pragma once struct param { int something; } class ISplitter { public: virtual ~ISplitter() = 0; virtual void useful() = 0; } ISplitter::~ISplitter() { /* Make sure base class destructor gets called */ } </code></pre> <p>And the main implementation header</p> <pre><code>//CSplitter.h #pragma once #include "CHelper.h" #include "ISplitter.h" class CSplitter : public ISplitter { private: CHelper hlp; public: ~CSplitter(); void useful(); } </code></pre> <p>Some helper class</p> <pre><code>//CHelper.h #pragma once #include "ISplitter.h" // I need the struct // Class definition should go here but is irrelevant </code></pre> <p>Now the problem is that the linker generates an error that tells me the destructor: ISplitter::~ISplitter(void) has been multiply declared and the system will not build. Error:</p> <pre><code>CHelper.obj : error LNK2005: "public: virtual __cdecl ISplitter::~ISplitter(void)" (??1ISplitter@@UEAA@XZ) already defined in CSplitter.obj </code></pre> <p>What is the correct way to fix this? I have placed the destructor in ISplitter.cpp, but I am worried this may not work if I dynamically load the library and upcast the base class to ISplitter.</p>
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    1. COPlease post real code. And the answer is to move the destructor definition to a.cpp file.
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      1. POWhere should the pure virtual destructor be declared?
      1. USNeil Butterworth
    2. COpossible duplicate of [Pure virtual destructor in C++](http://stackoverflow.com/questions/630950/pure-virtual-destructor-in-c)
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    3. COThe real code is proprietary
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