abseil-upgrade-duration-conversions¶
Finds calls to absl::Duration
arithmetic operators and factories whose
argument needs an explicit cast to continue compiling after upcoming API
changes.
The operators *=
, /=
, *
, and /
for absl::Duration
currently
accept an argument of class type that is convertible to an arithmetic type. Such
a call currently converts the value to an int64_t
, even in a case such as
std::atomic<float>
that would result in lossy conversion.
Additionally, the absl::Duration
factory functions (absl::Hours
,
absl::Minutes
, etc) currently accept an int64_t
or a floating-point
type. Similar to the arithmetic operators, calls with an argument of class type
that is convertible to an arithmetic type go through the int64_t
path.
These operators and factories will be changed to only accept arithmetic types to prevent unintended behavior. After these changes are released, passing an argument of class type will no longer compile, even if the type is implicitly convertible to an arithmetic type.
Here are example fixes created by this check:
std::atomic<int> a;
absl::Duration d = absl::Milliseconds(a);
d *= a;
becomes
std::atomic<int> a;
absl::Duration d = absl::Milliseconds(static_cast<int64_t>(a));
d *= static_cast<int64_t>(a);
Note that this check always adds a cast to int64_t
in order to preserve the
current behavior of user code. It is possible that this uncovers unintended
behavior due to types implicitly convertible to a floating-point type.