give it a shot

std/assembly/array.ts

@@ -34,6 +34,22 @@ export class Array<T> extends ArrayBufferView {
 
   constructor(length: i32 = 0) {
     super(length, alignof<T>());
+    if (isReference<T>()) {
+      if (!isNullable<T>()) {
+        let cur = this.dataStart;
+        let end = cur + (<usize>length << alignof<T>());
+        while (cur < end) {
+          // TODO: probably a common reason for complaints of T not having a default ctor. what if
+          // the array ctor would also take default arguments, like `new Array<Ref>(10, ...args)`?
+          store<T>(cur,
+            isString<T>()
+              ? "" // no need to instantiate
+              : RETAIN<T,this>(instantiate<T>(), this)
+          );
+          cur += sizeof<T>();
+        }
+      }
+    }
     this.length_ = length;
   }
 

std/assembly/runtime.ts

@@ -19,7 +19,7 @@ import { HEAP_BASE, memory } from "./memory";
 // Changes the size of a previously allocated, but not yet registered, runtime object, for
 // example when a pre-allocated buffer turned out to be too small or too large. This works by
 // aligning dynamic allocations to actual block size internally so in the best case REALLOCATE
-// only updates payload size while in the worst case moves the object to larger a block.
+// only updates payload size while in the worst case moves the object to a larger block.
 //
 // DISCARD(ref)
 // ------------