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+.. title:: clang-tidy - llvm-prefer-isa-or-dyn-cast-in-conditionals
+
+llvm-prefer-isa-or-dyn-cast-in-conditionals
+===========================================
+
+Looks at conditionals and finds and replaces cases of ``cast<>``,
+which will assert rather than return a null pointer, and
+``dyn_cast<>`` where the return value is not captured. Additionally,
+finds and replaces cases that match the pattern ``var &&
+isa<X>(var)``, where ``var`` is evaluated twice.
+
+.. code-block:: c++
+
+  // Finds these:
+  if (auto x = cast<X>(y)) {}
+  // is replaced by:
+  if (auto x = dyn_cast<X>(y)) {}
+
+  if (cast<X>(y)) {}
+  // is replaced by:
+  if (isa<X>(y)) {}
+
+  if (dyn_cast<X>(y)) {}
+  // is replaced by:
+  if (isa<X>(y)) {}
+
+  if (var && isa<T>(var)) {}
+  // is replaced by:
+  if (isa_and_nonnull<T>(var.foo())) {}
+
+  // Other cases are ignored, e.g.:
+  if (auto f = cast<Z>(y)->foo()) {}
+  if (cast<Z>(y)->foo()) {}
+  if (X.cast(y)) {}