Why is it hard to make Qt bindings?

[Tony]

On Thursday, 5 July 2018 at 12:52:49 UTC, Steven Schveighoffer 
wrote:
> On 7/5/18 4:42 AM, drug wrote:
>> There were several attempts to make Qt binding for dlang, but 
>> either they has failed or has been stalled. It would be nice 
>> to collect that experience. Considering 2.081 supports C++ 
>> special member (not all but majority) isn't it time to make 
>> another attempt or the problem is more complex?
>> Could you publish your experience in making Qt bindings here?
>
> I'm not a Qt user, but doesn't Qt require a special 
> pre-compiler, or even use the preprocessor in a way that is 
> difficult to duplicate in D?
>
Qt does have it's own pre-processor, but CopperSpice, a fork of 
Qt does not require that.

http://www.copperspice.com/