Copying a word list

What this C++ code-tracing question tests

This is a medium-difficulty code-tracing question that probes your understanding of how C++ handles object copying, particularly the interaction between explicit constructors, assignment operators, and the default behaviours the language provides. It's the kind of question that surfaces gaps in mental models about when and how copy semantics are invoked.

To answer correctly, you need to trace through the initialization and assignment of objects, understand the difference between copy construction and copy assignment, and recognize which operations invoke which code path. The question rewards careful reading of declarations and a clear grasp of C++ copy semantics—knowledge that matters in performance-critical code where unexpected copies can degrade latency.

• Copy constructors vs. copy assignment operators
• Implicit vs. explicit constructors and their interaction with copy mechanics
• Compiler-generated default copy behaviour
• Temporary objects and return-value optimisation contexts