I have complex template that uses a mixin to solve some problems. The mixin produces the error.  I thought template's were added in to the scope of the call? I guess the mixin is inserted before this happens. That isn't good ;/

Here is one place the error happens

	mixin("alias Func = extern("~functionLinkage!Q~") "~(ReturnType!Q).stringof~" function"~(Erase!(Parameters!Q)).stringof~";");

The mixin is required to get the proper linkage, as no other method has been found to do that. Everything works with built in types.

I saw somewhere that vibe.d had some way around this but the links are dead.

If it's not clear, I have to import the proper identifiers but every use of the template would require the user to add their import. Obviously not the way to go.

Take a read of this:

http://stackoverflow.com/a/32621854/1457000

The short of it is don't mixin stringof. Instead, mixin the actual template itself.

The functionLinkage might need to be string, but the types should remain literal. So try this:

mixin("alias Func = extern("~functionLinkage!Q~") (ReturnType!Q) function (Erase!(Parameters!Q));");


or something like that - don't concatenate strings of those, just make the string itself still say ReturnType!Q etc when you mix in. Then the scope will be correct.

On Wednesday, 20 July 2016 at 01:48:31 UTC, Adam D. Ruppe wrote:
> Take a read of this:
>
> http://stackoverflow.com/a/32621854/1457000
>
> The short of it is don't mixin stringof. Instead, mixin the actual template itself.
>
> The functionLinkage might need to be string, but the types should remain literal. So try this:
>
> mixin("alias Func = extern("~functionLinkage!Q~") (ReturnType!Q) function (Erase!(Parameters!Q));");
>
>
> or something like that - don't concatenate strings of those, just make the string itself still say ReturnType!Q etc when you mix in. Then the scope will be correct.

Thanks, it did work with some modification:

mixin("alias Func = extern("~functionLinkage!Q~") ReturnType!Q function(Erase!(Parameters!Q));");

No parenthesis around ReturnType or strange errors happen.