Compile error!

[sdv via Digitalmars-d]

import std.stdio;
import core.memory;

struct sQueue(T)
{
        struct sNode
        {
                T       mfPayload = T.init;
                union{
                        typeof(this)*   mfPrev;
                        shared(typeof(this)*)   mfShPrev;
                }
                union{
                        typeof(this)*   mfNext;
                        shared(typeof(this)*)   mfShNext;
                }
        }


        //shared(sQueueNode)    mfRoot;
        sNode   mfRoot;

        void pfPut(T v,sNode* r = null)
        {
                if(r is null) r = &this.mfRoot;
                shared auto n = new sNode(v);

        }

}


int main(string[] argv)
{
        auto b1 = new sQueue!uint;



    writeln("Hello D-World!");
        writeln("Hello D-World!");
        writeln("Hello D-World!");
    return 0;
}