| .. title:: clang-tidy - abseil-duration-division |
| ``absl::Duration`` arithmetic works like it does with integers. That means that |
| division of two ``absl::Duration`` objects returns an ``int64`` with any fractional |
| component truncated toward 0. See `this link <https://github.com/abseil/abseil-cpp/blob/29ff6d4860070bf8fcbd39c8805d0c32d56628a3/absl/time/time.h#L137>`_ for more information on arithmetic with ``absl::Duration``. |
| absl::Duration d = absl::Seconds(3.5); |
| int64 sec1 = d / absl::Seconds(1); // Truncates toward 0. |
| int64 sec2 = absl::ToInt64Seconds(d); // Equivalent to division. |
| assert(sec1 == 3 && sec2 == 3); |
| double dsec = d / absl::Seconds(1); // WRONG: Still truncates toward 0. |
| If you want floating-point division, you should use either the |
| ``absl::FDivDuration()`` function, or one of the unit conversion functions such |
| as ``absl::ToDoubleSeconds()``. For example: |
| absl::Duration d = absl::Seconds(3.5); |
| double dsec1 = absl::FDivDuration(d, absl::Seconds(1)); // GOOD: No truncation. |
| double dsec2 = absl::ToDoubleSeconds(d); // GOOD: No truncation. |
| assert(dsec1 == 3.5 && dsec2 == 3.5); |
| This check looks for uses of ``absl::Duration`` division that is done in a |
| floating-point context, and recommends the use of a function that returns a |
