Choosing the right clock for elapsed-time measurement

Understanding clock types and timing accuracy in C++

This medium-difficulty question tests your practical knowledge of C++ standard-library clocks and how to choose the right timing mechanism for a given use case. It's the kind of systems-level detail that matters in performance-critical environments, especially in low-latency trading and fintech where microsecond-level precision or monotonicity guarantees can be decisive.

The question requires you to reason about the properties of different clock types—such as how they respond to system-clock adjustments, their resolution, and whether they are guaranteed to move monotonically forward. A strong answer demonstrates that you understand not just the API, but the underlying behaviour and constraints of each clock, and can match the right tool to the measurement problem at hand.

• Monotonic vs. wall-clock time semantics
• Clock resolution and precision
• Behaviour under system-time adjustments
• Use cases for std::chrono::steady_clock, std::chrono::system_clock, and std::chrono::high_resolution_clock