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 information:
When the result is an
absl::Duration
and the first argument is anabsl::Time
.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.
Examples:
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);