copying: deep vs shallow copy module (clone() traps, copy constructors, serialization copy, records, defensive copies, collection copies), 17 contract tests

Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_017ic4b4X2xx7RrveVQU9R1N
2026-11-12 20:18:06 +05:30
parent 682b7b067c
commit 38fbd513c9
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+== 1. new ArrayList<>(list) and List.copyOf share the elements ==
+  boxes     = [Box(100), Box(2)]
+  viaCtor   = [Box(100), Box(2)]
+  viaCopyOf = [Box(100), Box(2)]
+  after boxes.add(Box(3)): viaCtor.size() = 2
+
+== 2. The deep version needs the element copy, so a stream or a loop ==
+  boxes = [Box(-1), Box(2), Box(3)]
+  deep  = [Box(100), Box(2), Box(3)]
+
+== 3. HashMap copy constructor: new map, same values ==
+  mCopy.get("k") = Box(55)
+
+== 4. 1-D primitive arrays: clone / copyOf are true copies ==
+  a = [99, 2, 3], clone = [1, 2, 3], copyOf = [1, 2, 3]
+
+== 5. 2-D arrays: the rows are shared ==
+  grid     = [[99, 2], [3, 4]]
+  shallow  = [[99, 2], [3, 4]]
+  deepGrid = [[1, 2], [3, 4]]
+
+== 6. Object arrays: copyOf copies references, not objects ==
+  arrCopy[0] = Box(77), same object: true