Don’t underestimate erasure. Theories for free is a useful thing. Granted c# generics allow for some useful meta-programming not possible in Java. But I’d rather take a language with no runtime reflection at all and a properly staged metaprogrammimg instead
> Don’t underestimate erasure. Theories for free is a useful thing.
Indeed, phantom types are wildly underappreciated. Long ago, I created an library [1] that ensures the type safety of any runtime generated programs you create using it. It does this by typing the various stacks that are in play at any given time, but every new generic type on the CLR ends up creating new type descriptors in global data structures (which aren't GC'd), so complex programs with deep stacks end up generating a lot of static, uncollectable data that just hangs around forever.
Being forced to pass the type as a parameter in a generic java method is pretty annoying... and it has nothing to do with metaprogramming, a simple generic factory method or even an “IfNotNull” generic function would need it.
Haven’t touched java since version 7 i think. But was pretty convinced they both have comparable type inference capabilities when it comes to parametric polymorphism.
The big difference between C# and java is the reification of the parameter values, inferred or not.
And the reification method choosen for C# gives you some extra metaprogramming capabilities, especially when combined with reflection.
My argument was that this can be provided design time instead (inference too) while retaining the extra safety of having theorems for free
