blob: c717ed389216a53ab492d4be837eb574f46d31b4 [file] [log] [blame]
.. title:: clang-tidy - abseil-time-subtraction
Finds and fixes ``absl::Time`` subtraction expressions to do subtraction
in the Time domain instead of the numeric domain.
There are two cases of Time subtraction in which deduce additional type
- When the result is an ``absl::Duration`` and the first argument is an
- When the second argument is a ``absl::Time``.
In the first case, we must know the result of the operation, since without that
the second operand could be either an ``absl::Time`` or an ``absl::Duration``.
In the second case, the first operand *must* be an ``absl::Time``, because
subtracting an ``absl::Time`` from an ``absl::Duration`` is not defined.
.. code-block:: c++
int x;
absl::Time t;
// Original - absl::Duration result and first operand is an absl::Time.
absl::Duration d = absl::Seconds(absl::ToUnixSeconds(t) - x);
// Suggestion - Perform subtraction in the Time domain instead.
absl::Duration d = t - absl::FromUnixSeconds(x);
// Original - Second operand is an absl::Time.
int i = x - absl::ToUnixSeconds(t);
// Suggestion - Perform subtraction in the Time domain instead.
int i = absl::ToInt64Seconds(absl::FromUnixSeconds(x) - t);