Reactive data

[crimaniak]

I want to have reactive variables like in this example:

```
USING_REACTIVE_DOMAIN(D)

// The two words
VarSignalT<string> firstWord  = MakeVar<D>(string( "Change" ));
VarSignalT<string> secondWord = MakeVar<D>(string( "me!" ));
// ...
SignalT<string> bothWords = firstWord + string( " " ) + 
secondWord;
```

from this page: 
http://schlangster.github.io/cpp.react/tutorials/BasicSignals.html

Is this possible to make it in D with 
https://github.com/lempiji/rx ? Is there other libraries exists 
for this topic?