Load dynamic libraries with no hand-written bindings!

[Paul Backus]

On Wednesday, 7 September 2022 at 15:35:29 UTC, Andrej Mitrovic 
wrote:
> As mentioned in the previous reply it seems that a function 
> typedef trips it up. If there was a way to filter it out, 
> that'd be great.

I think the root of the problem here is that 
`std.traits.isFunction` does not do exactly what you're assuming 
it does. Specifically, it evaluates to `true` for both function 
*symbols* and function *types*:

```d
import std.traits;

void fun() {}
static assert(isFunction!fun); // ok
static assert(isFunction!(typeof(fun))); // also ok!
```

In order to filter for just function *symbols*, you need to use a 
more elaborate test:

```d
         static if (
             is(typeof(&__traits(getMember, Module, member)) 
PtrType)
             && isFunctionPointer!PtrType
         ) {
             GetFunctionList = AliasSeq!(GetFunctionList, PtrType);
         }
```

This first checks whether you can take the member's address, and 
then, if you can, checks whether the type of that address is a 
function pointer. If I use the condition above in your reduced 
example, it compiles successfully, and the resulting list does 
not include the `typedef`.