import std.traits;

​

void main()

{

    alias V = Vec!Bool;

    alias P = Port!(V);

    pragma(msg, P.ElementType);

    static assert(__traits(hasMember, P, "ElementType"));

    static assert(hasMember!(P, "ElementType"));

}

​

mixin template SignalOps()

{

    static if(hasMember!(typeof(this), "ElementType")) { }

}

​

struct Bool {}

​

struct Port(SomeSignal)

{

    static if(hasMember!(SomeSignal, "ElementType"))

        alias ElementType = SomeSignal.ElementType;

    mixin SignalOps;

}

​

struct Vec(SomeSignal)

{

    alias ElementType = SomeSignal;

}