Thanks everyone for the info. It is very much appreciated!
What works for me right now is dealing with various packages (dub packages) and use them in projects. I previously made too many assumptions about how lib's and dll's work. It's much clearer now.
Where I still have a problem is with a plugin system. I would like to write an app that is plugin based. So that I can write a plugin to extend the functionality of the app. I imagine that I could copy the plugin into a folder from the (compiled) app and the app would be able to use the plugin without me having to recompile the app. I have been looking at LoadLibrary (https://dlang.org/library/core/runtime/runtime.load_library.html) and Object.factory (https://dlang.org/library/object/object.factory.html) but I don't quite get how to use them. I did find some info that was several years old. They mentioned that these functions are not yet ready for all platforms. I don't know if that has changed in the meantime. It is not clear from the documentation.
I would like to find some snippets or examples but that sort of resource for D is very hard to find online. Most of the time there are only some partial snippets where it turns out they only work under specific conditions or are restricted to one platform. Does D not supply some infrastructure for this kind of a task? It seams to me that is a very common approach to build an app. I expected there would be some out of the box solution for this in D. I would write the app and the plugins purely in D (no C bindings if possible).
I have tried to build a mini app which defines an interface for the plugins. The plugins then implement that interface. But when I want to load the plugin both LoadLibrary() and Object.factory() fail (I am aware that Object.factory() requires the full qualified class names).
Is there a recommended way of writing a simple plugin system that works on windows and linux? Maybe someone has a working example or knows a book that covers how to write a plugin system?
