Wipe them out.

What this C++ code-reading question tests

This is a medium-difficulty C++ question that assesses your ability to trace through code execution and predict output. It requires careful attention to language semantics, operator precedence, and standard library behavior—the kind of precision that matters when debugging production systems or optimizing tight loops.

To answer correctly, you need to understand how the code modifies a data structure, what each operation does in sequence, and what the final state looks like when printed. The question rewards candidates who can mentally execute code without running it, spot subtle effects of C++ features, and articulate the result clearly.

• Container semantics and state mutation
• Operator behavior and side effects
• Output formatting and string representation
• Careful reading of standard library documentation