If the function is comptime-known then you'll get a direct call, and you can mark it near the call site as being required to be comptime-known (e.g., by marking a function argument to another function with the "comptime" tag). To make it super explicit you can make a no-op function like `fn cknown(comptime f: anytype) @TypeOf(f) {return f;}` and then replace stuff like `foo(bar)` with `cknown(foo)(bar)`.

It's a tiny bit harder to force an indirect call if that's desired for some reason; I think you'd need to write a slightly longer never inlined helper function to strip the constness from the pointer. It's doable though, just not directly provided by the language.