Self-assigning a data holder

Understanding self-assignment behavior in C++ data holders

This is a hard C++ language-knowledge question that tests whether you understand the subtle pitfalls of object self-assignment and memory management. It's the kind of question interviewers ask to reveal gaps between textbook knowledge and real-world C++ intuition.

The problem requires you to trace through what happens when an object assigns itself to itself—a scenario that looks pathological but can occur in real code through aliasing or indirect references. You'll need to reason carefully about the order of operations, pointer validity, and whether resource cleanup happens before or after data is copied. This probes whether you instinctively think about self-assignment safety when designing assignment operators.

• Copy-and-swap idiom and self-assignment guards
• Resource lifecycle and dangling pointers
• Sequence of operations in assignment operators
• Move semantics vs. copy semantics