Am I unique?

What this C++ language-semantics question tests

This is a medium-difficulty C++ question that probes your understanding of how the language handles object identity, value semantics, and the behavior of standard library containers. It rewards careful reading of code flow and familiarity with the subtle differences between reference semantics and copy semantics in C++.

To answer correctly, you need to trace through the code execution, paying attention to how objects are created, copied, and compared. The question tests whether you understand not just what the code does, but why it produces its specific output. This is the kind of detail that separates candidates who have read the spec from those who have merely written code that happens to work.

• Object identity vs. object equality in C++
• Copy constructors and assignment semantics
• How standard containers manage their elements
• Output and side effects of comparison operations