1.. title:: clang-tidy - abseil-duration-unnecessary-conversion
2
3abseil-duration-unnecessary-conversion
4======================================
5
6Finds and fixes cases where ``absl::Duration`` values are being converted to
7numeric types and back again.
8
9Floating-point examples:
10
11.. code-block:: c++
12
13  // Original - Conversion to double and back again
14  absl::Duration d1;
15  absl::Duration d2 = absl::Seconds(absl::ToDoubleSeconds(d1));
16
17  // Suggestion - Remove unnecessary conversions
18  absl::Duration d2 = d1;
19
20  // Original - Division to convert to double and back again
21  absl::Duration d2 = absl::Seconds(absl::FDivDuration(d1, absl::Seconds(1)));
22
23  // Suggestion - Remove division and conversion
24  absl::Duration d2 = d1;
25
26Integer examples:
27
28.. code-block:: c++
29
30  // Original - Conversion to integer and back again
31  absl::Duration d1;
32  absl::Duration d2 = absl::Hours(absl::ToInt64Hours(d1));
33
34  // Suggestion - Remove unnecessary conversions
35  absl::Duration d2 = d1;
36
37  // Original - Integer division followed by conversion
38  absl::Duration d2 = absl::Seconds(d1 / absl::Seconds(1));
39
40  // Suggestion - Remove division and conversion
41  absl::Duration d2 = d1;
42
43Unwrapping scalar operations:
44
45.. code-block:: c++
46
47  // Original - Multiplication by a scalar
48  absl::Duration d1;
49  absl::Duration d2 = absl::Seconds(absl::ToInt64Seconds(d1) * 2);
50
51  // Suggestion - Remove unnecessary conversion
52  absl::Duration d2 = d1 * 2;
53
54Note: Converting to an integer and back to an ``absl::Duration`` might be a
55truncating operation if the value is not aligned to the scale of conversion.
56In the rare case where this is the intended result, callers should use
57``absl::Trunc`` to truncate explicitly.
58