.. title:: clang-tidy - llvm-redundant-casting

llvm-redundant-casting
======================

Points out uses of ``cast<>``, ``dyn_cast<>``, ``isa<>`` and their ``or_null``
variants that are unnecessary because the argument already is of the target
type, or a derived type thereof.

.. code-block:: c++

  struct A {};
  A a;
  // Finds:
  A x = cast<A>(a);
  // replaced by:
  A x = a;

  struct B : public A {};
  B b;
  // Finds:
  A y = cast<A>(b);
  // replaced by:
  A y = b;

  struct C : public A {};
  C c;
  // Finds:
  bool r1 = isa<A>(a)    // always true
  bool r2 = isa<A>(b)    // always true
  bool r3 = isa<B, C>(c) // always true

Supported functions:
 - ``llvm::cast``
 - ``llvm::cast_or_null``
 - ``llvm::cast_if_present``
 - ``llvm::dyn_cast``
 - ``llvm::dyn_cast_or_null``
 - ``llvm::dyn_cast_if_present``
 - ``llvm::isa``
 - ``llvm::isa_and_nonnull``
 - ``llvm::isa_and_present``