38 lines
1.2 KiB
ReStructuredText
38 lines
1.2 KiB
ReStructuredText
|
.. title:: clang-tidy - bugprone-standalone-empty
|
||
|
|
|
||
|
|
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:
|
||
|
|
|
||
|
|
.. code-block:: c++
|
||
|
|
|
||
|
|
std::vector<int> v;
|
||
|
|
...
|
||
|
|
v.empty();
|
||
|
|
|
||
|
|
A call to ``clear()`` would appropriately clear the contents of the range:
|
||
|
|
|
||
|
|
.. code-block:: c++
|
||
|
|
|
||
|
|
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.
|