nicer test

std/range/package.d

@@ -4423,21 +4423,13 @@ pure unittest
     auto zz = z.save;
 }
 
-@safe pure unittest
+pure unittest
 {
     import std.typecons : tuple;
-
-    static class RefRange
-    {
-        @safe: pure:
-        this(int front){ this.front = front; }
-        int front;
-        enum empty = false;
-        void popFront(){ front++; }
-        RefRange save(){ return new RefRange(front); }
-    }
-
-    auto z1 = zip(new RefRange(0), new RefRange(1));
+
+    auto r1 = [0,1,2];
+    auto r2 = [1,2,3];
+    auto z1 = zip(refRange(&r1), refRange(&r2));
     auto z2 = z1.save;
     z1.popFront();
     assert(z1.front == tuple(1,2));