| .. 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. |
