line2 := Line{name: "diagonal", q: Point3D{1, 1, 1}}      // zero value for line2.Object.color, line2.p
</pre>

<p>
but field selectors may not denote overlapping fields:
</p>

<pre>
obj   := Object{"edge", "black"}
line3 := Line{Object: obj, name: "diagonal"}              // invalid: name denotes a field inside Object
</pre>