llvm/clang-tools-extra/docs/clang-tidy/checks/misc/misplaced-const.rst

.. title:: clang-tidy - misc-misplaced-const

misc-misplaced-const
====================

This check diagnoses when a ``const`` qualifier is applied to a ``typedef``/
``using`` to a pointer type rather than to the pointee, because such constructs
are often misleading to developers because the ``const`` applies to the pointer
rather than the pointee.

For instance, in the following code, the resulting type is ``int * const``
rather than ``const int *``:

.. code-block:: c++

  typedef int *int_ptr;
  void f(const int_ptr ptr) {
    *ptr = 0; // potentially quite unexpectedly the int can be modified here
    ptr = 0; // does not compile
  }

The check does not diagnose when the underlying ``typedef``/``using`` type is a
pointer to a ``const`` type or a function pointer type. This is because the
``const`` qualifier is less likely to be mistaken because it would be redundant
(or disallowed) on the underlying pointee type.