.. title:: clang-tidy - bugprone-casting-through-void

bugprone-casting-through-void
=============================

Detects unsafe or redundant two-step casting operations involving ``void*``.

Two-step type conversions via ``void*`` are discouraged for several reasons.

- They obscure code and impede its understandability, complicating maintenance.
- These conversions bypass valuable compiler support, erasing warnings related
  to pointer alignment. It may violate strict aliasing rule and leading to
  undefined behavior.
- In scenarios involving multiple inheritance, ambiguity and unexpected outcomes
  can arise due to the loss of type information, posing runtime issues.

In summary, avoiding two-step type conversions through ``void*`` ensures clearer code,
maintains essential compiler warnings, and prevents ambiguity and potential runtime
errors, particularly in complex inheritance scenarios.

Examples:

.. code-block:: c++

   using IntegerPointer = int *;
   double *ptr;

   static_cast<IntegerPointer>(static_cast<void *>(ptr)); // WRONG
   reinterpret_cast<IntegerPointer>(reinterpret_cast<void *>(ptr)); // WRONG
   (IntegerPointer)(void *)ptr; // WRONG
   IntegerPointer(static_cast<void *>(ptr)); // WRONG