Fact checking for my talk

[Lodovico Giaretta via Digitalmars-d]

On Saturday, 13 August 2016 at 17:27:35 UTC, Chris Wright wrote:
> On Sat, 13 Aug 2016 16:28:57 +0000, deadalnix wrote:
>> C# use generic (aka type erasure) for objects
>
> Incorrect:
>
> ---
> public class Foo {}
> var fooList = new List<Foo>();
> var objectList = (List<object>)(object)fooList;
> ---
>
> This throws InvalidCastException. Which isn't possible with 
> type erasure. The equivalent Java code will not throw an 
> exception because, after type checking, List<T> is converted to 
> List<Object>. That's the definition of type erasure.
>
> Similarly, you can inspect the methods on List<Foo> at runtime 
> in C# and see that, for instance, the `Add` method takes a 
> parameter of type Foo. And you can look at the type of 
> `fooList` with reflection and see that it's List with generic 
> parameter 0 set to Foo. That's stuff you can't do with type 
> erasure.
>
> The code that .NET generates for a generic instantiation with 
> class type is different from the code it generates for a 
> generic instantiation for a struct simply because structs are 
> not like classes.

I guess what he meant is that there will be just one code 
generation, as all class types are just pointers. So on this side 
it behaves like Java (if we only talk about reference types).
The difference is that the .NET IL retains complete type 
information for the variables, even if it dispatches to the same 
instantiation.