Added Area-Library label.

One issue is how we get a class mirror for a given instantiation in the first place. Maybe have an optional argument to reflectClass that is a list of type arguments. The newInstance doesn't have to deal with the problem.

Added Accepted label.

Issue #21009 has been merged into this issue.

This comment was originally written by @jonaskello

Type arguments to reflectClass sounds good to me. My scenario is Message/Handler. Something like this:

Using di package to bind Types to implementation:

bind(TypeLiteral<IMessageHandler<FooMessage>>, toImplementation: FooMessageHandler);
bind(TypeLiteral<IMessageHandler<BarMessage>>, toImplementation: BarMessageHandler);

When I then receive a message I want to be able to dynamically construct a Type for the handler of the message received. If reflectClass had type arguments I guess I could do something like this:

var msg = ReceiveMessage();
var handlerType = reflectClass(IMesssageHandler, msg.runtimeType);
var handler = injector.get(handlerType);
handler.Handle(msg);

I'm also be interested in work-arounds or alternatives that would solve this scenario in the current version.

This comment was originally written by @jonaskello

Yes I think this is a basic function that should have been added long ago. Maybe it is because the title is a bit off. In general I think requests that are formulated as a problem description is better than those formulated as a proposed solution. Maybe something like "Cannot get class mirror for generic instantiation when type arguments are not known until runtime." Should we create a new issue?

Is this something that requires DEP or can be implemented and submitted in a PR?

I believe this is subsumed by the feature proposed in #26012 (even though that issue says at first that it isn't).

I think we can close this since it's covered by type arguments in reflectType