Given we use a base-class type within the renderer for the rasterizer (RasterizerInterface), we want to allow renderers to perform more complex initialization if they need to do such a thing. This makes it important to reserve type information. Given the OpenGL renderer is quite simple settings-wise, this is just a simple shuffling of the initialization code. For something like Vulkan however this might involve doing something like: // Initialize and call rasterizer-specific function that requires // the full type of the instance created. auto raster = std::make_unique<VulkanRasterizer>(some, params); raster->CallSomeVulkanRasterizerSpecificFunction(); // Assign to base class variable rasterizer = std::move(raster)