| .. title:: clang-tidy - bugprone-unique-ptr-array-mismatch |
| |
| bugprone-unique-ptr-array-mismatch |
| ================================== |
| |
| Finds initializations of C++ unique pointers to non-array type that are |
| initialized with an array. |
| |
| If a pointer ``std::unique_ptr<T>`` is initialized with a new-expression |
| ``new T[]`` the memory is not deallocated correctly. A plain ``delete`` is used |
| in this case to deallocate the target memory. Instead a ``delete[]`` call is |
| needed. A ``std::unique_ptr<T[]>`` uses the correct delete operator. The check |
| does not emit warning if an ``unique_ptr`` with user-specified deleter type is |
| used. |
| |
| The check offers replacement of ``unique_ptr<T>`` to ``unique_ptr<T[]>`` if it |
| is used at a single variable declaration (one variable in one statement). |
| |
| Example: |
| |
| .. code-block:: c++ |
| |
| std::unique_ptr<Foo> x(new Foo[10]); // -> std::unique_ptr<Foo[]> x(new Foo[10]); |
| // ^ warning: unique pointer to non-array is initialized with array |
| std::unique_ptr<Foo> x1(new Foo), x2(new Foo[10]); // no replacement |
| // ^ warning: unique pointer to non-array is initialized with array |
| |
| D d; |
| std::unique_ptr<Foo, D> x3(new Foo[10], d); // no warning (custom deleter used) |
| |
| struct S { |
| std::unique_ptr<Foo> x(new Foo[10]); // no replacement in this case |
| // ^ warning: unique pointer to non-array is initialized with array |
| }; |
| |
| This check partially covers the CERT C++ Coding Standard rule |
| `MEM51-CPP. Properly deallocate dynamically allocated resources |
| <https://wiki.sei.cmu.edu/confluence/display/cplusplus/MEM51-CPP.+Properly+deallocate+dynamically+allocated+resources>`_ |
| However, only the ``std::unique_ptr`` case is detected by this check. |