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POVisualStudio C++ Linker problem with template classes
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  1. POVisualStudio C++ Linker problem with template classes
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    copied!<p>I still can't get it to work..</p> <p>After I had to separate implementation from definition of one of my generic classes because of a forward declaration, i now get Linker errors when trying to build.</p> <p>IShader.h:</p> <pre><code>template &lt;typename ShadeType&gt; class IShader { public: template &lt;typename T&gt; bool getProperty(const std::string&amp; propertyName, ShaderProperty&lt;T&gt;** outProp); }; </code></pre> <p>so it's a generic class with a generic member function with a different generic type</p> <p>implementation looks like this:</p> <pre><code>#include "MRIShader.h" template &lt;typename ShadeType&gt; template &lt;typename T&gt; bool IShader&lt;ShadeType&gt;::getProperty(const std::string&amp; propertyName, ShaderProperty&lt;T&gt;** outProp){ std::map&lt;std::string, IShaderProperty* &gt;::iterator i = m_shaderProperties.find(propertyName); *outProp = NULL; if( i != m_shaderProperties.end() ) { *outProp = dynamic_cast&lt;ShaderProperty&lt;T&gt;*&gt;( i-&gt;second ); return true; } return false; } </code></pre> <p>but i get Linker errors like this one:</p> <pre><code>error LNK2001: Nicht aufgelöstes externes Symbol ""public: bool __thiscall IShader&lt;class A_Type&gt;::getProperty&lt;bool&gt;(class std::basic_string&lt;char,struct std::char_traits&lt;char&gt;,class std::allocator&lt;char&gt; &gt; const &amp;,class ShaderProperty&lt;bool&gt; * *)" (??$getProperty@_N@?$IShader@VA_Type@@@@QAE_NABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@PAPAV?$ShaderProperty@_N@@@Z)". SceneParser.obj </code></pre> <p>for bool, but also for many other types. I already read through this article: <a href="http://www.parashift.com/c++-faq-lite/templates.html" rel="nofollow noreferrer">http://www.parashift.com/c++-faq-lite/templates.html</a></p> <p>but adding </p> <pre><code>templace class IShader&lt;bool&gt;; </code></pre> <p>in the end of IShader.cpp doesn't solve the problem. I also tried to add the 'export' keyword before the keyword 'template' in the implementation, but this just gives me a syntax error.</p> <p>What's the proper way to declare and implement my template class, which has templated member methods (with a different template type!) in separate files (.h and .cpp) without getting Linker errors?</p> <p>thanks!</p>
 

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