+ * Returns: Zero on success, %$-1$% on failure.
+ *
+ * Use: Initialize the benchmark state. On success, the timer state
+ * still needs to be calibrated (use @bench_calibrate@) before
+ * it can be used, but this will be done automatically by
+ * @bench_measure@ if it's not done by hand earlier. The timer
+ * is now owned by the benchmark state and will be destroyed by
+ * @bench_destroy@.