bugprone-standalone-empty¶
Warns when empty()
is used on a range and the result is ignored. Suggests
clear()
if it is an existing member function.
The empty()
method on several common ranges returns a Boolean indicating
whether or not the range is empty, but is often mistakenly interpreted as
a way to clear the contents of a range. Some ranges offer a clear()
method for this purpose. This check warns when a call to empty returns a
result that is ignored, and suggests replacing it with a call to clear()
if it is available as a member function of the range.
For example, the following code could be used to indicate whether a range is empty or not, but the result is ignored:
std::vector<int> v;
...
v.empty();
A call to clear()
would appropriately clear the contents of the range:
std::vector<int> v;
...
v.clear();
Limitations:
Doesn’t warn if
empty()
is defined and used with the ignore result in the class template definition (for example in the library implementation). These error cases can be caught with[[nodiscard]]
attribute.