Template constraints for reference/value types?

[Lodovico Giaretta via Digitalmars-d-learn]

On Tuesday, 6 September 2016 at 20:46:54 UTC, Jon Degenhardt 
wrote:
> Is there a way to constrain template arguments to reference or 
> value types? I'd like to do something like:
>
> T foo(T)(T x)
>     if (isReferenceType!T)
> { ... }
>
> --Jon

You can use `if(is(T : class) || is(T : interface))`.

If you also need other types, std.traits contains a bunch of 
useful templates: isArray, isAssociativeArray, isPointer, ...