What is the best way to program over "abstract" types in D?

[Adam D. Ruppe]

On Saturday, 23 November 2019 at 16:38:30 UTC, Ola Fosheim 
Grøstad wrote:
> Ok, thanks, that is worth exploring. Right now the objects I am 
> looking at are pure values, so that might be a bit verbose 
> though.

In many cases, you can just do

auto c = scoped!Class(args, to, ctor);

and it mostly works. The only time you need to explicitly mention 
the interface line is when passing to a template by value (since 
then it will try to copy the scoped instance and that is a 
compile error).

So you can frequently do it less verbosely than I did there.

> I also guess LTO happens too late in the process to carry over 
> information about whether virtuals have been specialised or not.

I don't know really. Maybe I used the wrong argument to ldc too 
to enable it.

> Yes, I am starting with structs, because pure values ought to 
> be easier on the optimizer. So one should be able to go to a 
> fairly high abstraction level and still get good performance.

Yeah, just I expect classes will win overall :) We'll see, I 
suppose.