C# cleaner signal emission (v2)

[OlliO6]

Provides a type safe way to emit signals in c#.

Previous:

EmitSignal(SignalName.SomethingHappened, arg1, arg2, arg3);
// This does not have syntax highlighting and compile error when signature is not met.

Now:

GetEmitter<SignalEmitter.SomethingHappened>().Emit(arg1, arg2, arg3);

I also implemented that enums can be used.

Previous PR: C#: Cleaner signal emission
Can't be archieved seamlessly (allocations or pullotion)

Alternative: C#: Generate strongly-typed method to raise signal events and fix event accessibility

• Pollutes classes
• Shorter code
• Guidelines

[dannflor]

I'm a huge fan of this. I like how the type is leveraged for better compile-time checking and I especially need the enums as args. Since this is going to break the signal emission API, I say the sooner we merge the better 👍

[kleonc]

cc @raulsntos @neikeq

[raulsntos]

This PR does not break compatibility so there's no rush to merge it.

I'd love to have a way to emit signals using a typed method but it's not clear which is the best approach. I personally favor my own implementation (#68233) over this PR.

My opinion on this PR:

• I don't like how much more verbose this is compared to my version.
• I prefer to follow the .NET event conventions more closely.
• Accessing the Bounds property uses a callvirt, not sure how much of an impact this has on performance.
• The new() constraint uses Activator.CreateInstance() which uses reflection, we may be able to avoid this in .NET 7 with static abstract members.

[OlliO6]

I kinda agree to the verbosity of this.
Would it be better to use default instead of new?

[raulsntos]

Would it be better to use default instead of new?

I think so, I'd also recommend using the struct constraint since we know all the TSignalEmitter types will always be structs and that will avoid the nullability warning.

[aaronfranke]

The alternative implementation from @raulsntos was merged in PR #68233, so I'm closing this PR as superseded. Thank you for working on this!