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1.. title:: clang-tidy - readability-ambiguous-smartptr-reset-call2 3readability-ambiguous-smartptr-reset-call4=========================================5 6Finds potentially erroneous calls to ``reset`` method on smart pointers when7the pointee type also has a ``reset`` method. Having a ``reset`` method in8both classes makes it easy to accidentally make the pointer null when9intending to reset the underlying object.10 11.. code-block:: c++12 13 struct Resettable {14 void reset() { /* Own reset logic */ }15 };16 17 auto ptr = std::make_unique<Resettable>();18 19 ptr->reset(); // Calls underlying reset method20 ptr.reset(); // Makes the pointer null21 22Both calls are valid C++ code, but the second one might not be what the23developer intended, as it destroys the pointed-to object rather than resetting24its state. It's easy to make such a typo because the difference between25``.`` and ``->`` is really small.26 27The recommended approach is to make the intent explicit by using either member28access or direct assignment:29 30.. code-block:: c++31 32 std::unique_ptr<Resettable> ptr = std::make_unique<Resettable>();33 34 (*ptr).reset(); // Clearly calls underlying reset method35 ptr = nullptr; // Clearly makes the pointer null36 37The default smart pointers and classes that are considered are38``std::unique_ptr``, ``std::shared_ptr``, ``boost::shared_ptr``. To specify39other smart pointers or other classes use the :option:`SmartPointers` option.40 41 42.. note::43 44 The check may emit invalid fix-its and misleading warning messages when45 specifying custom smart pointers or other classes in the46 :option:`SmartPointers` option. For example, ``boost::scoped_ptr`` does not47 have an ``operator=`` which makes fix-its invalid.48 49.. note::50 51 Automatic fix-its are enabled only if :program:`clang-tidy` is invoked with52 the `--fix-notes` option.53 54 55Options56-------57 58.. option:: SmartPointers59 60 Semicolon-separated list of fully qualified class names of custom smart61 pointers. Default value is `::std::unique_ptr;::std::shared_ptr;62 ::boost::shared_ptr`.63