How to split strings into AA using phobos

[Arun Chandrasekaran via Digitalmars-d-learn]

A typical example would be to split the HTTP query string into an 
AA.

vibe.d has req.queryString, but no convenient wrapper to access 
it as an AA.

http://localhost/hello?name=abc&id=123

I've got this far.

        auto arr = req.queryString.splitter('&').map!(a => 
a.splitter('='));

Thanks