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1.. title:: clang-tidy - abseil-duration-division2 3abseil-duration-division4========================5 6``absl::Duration`` arithmetic works like it does with integers. That means that7division of two ``absl::Duration`` objects returns an ``int64`` with any8fractional component truncated toward 0.9See `this link <https://github.com/abseil/abseil-cpp/blob/29ff6d4860070bf8fcbd39c8805d0c32d56628a3/absl/time/time.h#L137>`_10for more information on arithmetic with ``absl::Duration``.11 12For example:13 14.. code-block:: c++15 16 absl::Duration d = absl::Seconds(3.5);17 int64 sec1 = d / absl::Seconds(1); // Truncates toward 0.18 int64 sec2 = absl::ToInt64Seconds(d); // Equivalent to division.19 assert(sec1 == 3 && sec2 == 3);20 21 double dsec = d / absl::Seconds(1); // WRONG: Still truncates toward 0.22 assert(dsec == 3.0);23 24If you want floating-point division, you should use either the25``absl::FDivDuration()`` function, or one of the unit conversion functions such26as ``absl::ToDoubleSeconds()``. For example:27 28.. code-block:: c++29 30 absl::Duration d = absl::Seconds(3.5);31 double dsec1 = absl::FDivDuration(d, absl::Seconds(1)); // GOOD: No truncation.32 double dsec2 = absl::ToDoubleSeconds(d); // GOOD: No truncation.33 assert(dsec1 == 3.5 && dsec2 == 3.5);34 35 36This check looks for uses of ``absl::Duration`` division that is done in a37floating-point context, and recommends the use of a function that returns a38floating-point value.39