Wrapping an arbitrary class/struct API

[John Colvin]

On Saturday, 24 August 2013 at 13:14:30 UTC, Joseph Rushton 
Wakeling wrote:
> Hello all,
>
> (This accidentally got posted as a reply to someone else's 
> thread -- I'm reposting in order to make sure that thread 
> doesn't get diverted.)
>
> Suppose that I have a struct like e.g.:
>
>     struct A
>     {
>         void foo(int n) { ... }
>         void foo(Range)(Range r) { ... }
>         int bar() { ... }
>         int bar(double x) { ... }
>         // ... and others ...
>     }
>
> ... an I want to wrap it in another struct, B.  If I do this 
> manually it would be something like,
>
>     struct B
>     {
>         private A a;
>         void foo(int n) { return a.foo(n); }
>         void foo(Range)(Range r) { return a.foo(r); }
>         // ... etc ...
>     }
>
> But suppose that I don't a priori know the list of functions 
> (and function arguments) that need to be wrapped.  How could I 
> go about working this out, with a generic programming approach, 
> i.e. _without_ manually writing the individual cases?
>
> More specifically, how could I work this out limited to a 
> specific function of A (say, foo) ... ?
>
> Thanks & best wishes,
>
>     -- Joe

You might want to look at std.typecons.Proxy
also, opDispatch is a very powerful tool for doing this sort of 
thing.