Chrono and Formatting

Durations and clocks

using namespace std::chrono_literals;

auto timeout = 250ms;
auto start = std::chrono::steady_clock::now();

• steady_clock: elapsed time and benchmarking.
• system_clock: wall-clock time.
• duration literals such as 10ms, 2s, and 5min improve readability.

Measuring elapsed time

auto start = std::chrono::steady_clock::now();
do_work();
auto end = std::chrono::steady_clock::now();
auto elapsed = end - start;

Converting durations

auto ms = std::chrono::duration_cast<std::chrono::milliseconds>(elapsed);

std::format and std::print

auto msg = std::format("{} took {} ms", name, ms.count());
std::print("{}\n", msg);

Practical guidance

• Use steady_clock for timeouts and measurements.
• Use system_clock for timestamps the user sees.
• Prefer std::format over hand-built stream chains when formatting gets nontrivial.