Callback Setup and Call

What this C++ callback and function-pointer question tests

This is a medium-difficulty C++ code-reading question that probes your understanding of callbacks, function pointers, and how they interact with scope and type binding. It's the kind of question used to filter candidates who have hands-on experience with C++ rather than just textbook knowledge.

To answer correctly, you need to trace through the setup phase (where callbacks are registered or configured), understand what gets bound at each step, and then mentally execute the call sequence to determine the output. The question rewards close attention to detail—subtle differences in pointer type, the order of operations, or scope can all affect the result.

• Function pointers and their syntax
• Callback registration and invocation patterns
• Type safety and function signatures
• Scope and lifetime of callable objects