Variadic arguments template method specialization-CodePudding

I'm in a process of implementing loadAsset method in my asset manager implementation. I've tried using variadic arguments template method with following signature:

class AssetManager {
public:
   template <typename AssetType, typename... Args>
   void loadAsset(std::string_view name, const Args &...args);
...
};

And following specialization in .cpp file:

template <>
void AssetManager::loadAsset<Texture, std::string>(std::string_view name, const std::string &path) {...}

template void AssetManager::loadAsset<Texture, std::string>(std::string_view, const std::string &path); //explicit instantiation

However when trying to invoke loadAsset method like so:

m_assetManager->loadAsset<NOX::Texture>("texture", "assets/textures/texture.jpg");

I get the following error:

error LNK2019: unresolved external symbol "public: void __cdecl NOX::AssetManager::loadAsset<class NOX::Texture,char [28]>(class std::basic_string_view<char,struct std::char_traits<char> >,char const (&)[28])" (??$loadAsset@VTexture@NOX@@$$BY0BM@D@AssetManager@NOX@@QEAAXV?$basic_string_view@DU?$char_traits@D@std@@@std@@AEAY0BM@$$CBD@Z) referenced in function "public: __cdecl ExampleApplication::ExampleApplication(struct NOX::ApplicationSpecification const &)" (??0ExampleApplication@@QEAA@AEBUApplicationSpecification@NOX@@@Z)

How can I prevent that from happening? I'm using C 17 and can't use C 20.

CodePudding user response：

If you specialize a template in a cpp file, that'll be available in the given file, but not externally (unless, of course, if you instantiate it manually). Best way to do it is to move all template definitions to header.