This is something I'll look for the next version of DerelictUtil, which I'm currently working on.

loadSymbols maybe can use the template and mixin to auto generate code.

Yeah, maybe. This isn't a real pressing issue for me, though.

what is the pressing issue?

Nothing, really. My priority right now is finishing off my refactor of DerelictGL3 and then updating all of the Derelict packages to use the upcoming DerelictUtil 3.0. I simply mean there's no important reason to merge this and tag a new release of the current version of DerelictUtil. It's an enhancement, not a bug fix. And I'm not even sure it's worth doing.

When I can make the time, I'll try this out locally on my 3.0 branch and transform one of the other packages to use it. With your implementation, I'm worried about code bloat from all the multiple instantiations of the template. Derelict 2 used a templated function like this and I intentionally changed it to the current implementation in Derelict 3. Getting rid of the cast to void** isn't much of a benefit if there's a marked increase in the binary. But I'm willing to play around with it and see where it leads me.

it can try.
I add buildhrper.
and the test :
https://github.com/putaolabs/DerelictPQ/blob/master/source/derelict/pq/functiond.d
https://github.com/putaolabs/DerelictPQ/blob/master/source/derelict/pq/package.d

in loadSymbols() only two line code:

import derelict.util.buildhelper;
mixin(BuildLoadSymbols!(derelict.pq.functiond));

The point is, I'm not going to be merging this into the current release at all. After I experiment with it for myself, I will add it to DerelictUtil 3.0 and update all of the packages to use it iff I determine there is nothing deterimental in doing so. I don't have time to investigate right now, but it is on my TODO list and I will keep this open until I can make time for it.

ok.