TypeInfo_Interface from runtime string?

[Basile B. via Digitalmars-d-learn]

On Wednesday, 22 June 2016 at 15:15:51 UTC, Thalamus wrote:
> Hi everyone,
>
> My project includes lots of .Net interop via C linkage. One of 
> the things I need to do is refer in C# to an interface declared 
> in the D code, and then to actually work with the interface 
> concretely in the D layer. So, I need to get a 
> TypeInfo_Interface object from a string passed in from C#.
>
> The problem isn't in marshaling the string between C# and D, 
> but rather what to do with the string once I have it in D.
>
> So in the D code, where interfaceName is the fully qualified 
> name of an interface, e.g.  "MyPackage.MyModule.MyInterface", 
> what I would like is something like:
>
>
> TypeInfo_Interface theInterface = new 
> TypeInfo_Interface(interfaceName);
>
>
> But there's no such constructor.

No need for a constructor. typeid() returns a static instance 
that's pre-allocated.

> Apologies if this seems like it should be obvious, but I 
> couldn't find anything in the forums or the wider web. :)

No problem. What you need to do is to create a registry with all 
the possible TypeInfo_Interfaces. This registry will have the 
form of an associative array. Each TypeInfo_Interface will be 
selectable with the fully qualified string, for example:

     __gshared TypeInfo_Interface[string] registry;

     interface Foo{}
     interface Bar{}

     static this()
     {
         registry[typeid(Foo).toString] = typeid(Foo);
         registry[typeid(Bar).toString] = typeid(Bar);
     }

That's the basic idea but with introspection (foreach(member; 
traits....) you should be able to automate the creation of the 
registry, in a smarter way.