For this, I need an interface and maybe a container for resolving my instances. But how you do this in C++?
In the same way. The difference is that where you “program to an interface” in C#, you “program to a base class” in C++. Additionally, you have extra tools in C++ that you do not have in C# (for example, policy-based templates implement dependency injection chosen at compilation time).
In C++ you’re use a reference to an object, this is the way to use DI in C++, right?
No; this is not the way to use DI, this is a way to use DI in C++.
Also consider:
- use a pointer to an object (or smart pointer, depending on the case)
- use a template argument for a policy (for an example, see std::default_delete use in smart pointers)
- use lambda calcullus with injected functors/predicates.
In C# I’ve a “bad class/bad project/assembly” which register all my instance into a static container at the program start.
If I understand correctly, you set all your data in this static container and use it all over the application. If this is the case, then you do not use dependency injection correctly, because this breaks Demeter’s Law.
is this possible in C++?
Yes, it is perfectly possible (but you shouldn’t do it, due to it breaking Demeter’s law). Have a look at boost::any (this will allow you to store heterogenous objects in a container, similar to storing objects by object reference in C#).
Are you using dependency injection or whatever it is called in C++?
Yes (and it is called dependency injection 🙂 ).
If yes, how you’re use it?
As I described above (policy template arguments, injected functors and predicates as reusable components, injecting objects by reference, pointer smart pointer or value).