[libcxx-commits] [libcxx] [libc++] Add an ABI setting to harden unique_ptr<T[]>::operator[] (PR #91798)

[Artem Dergachev via libcxx-commits]

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@@ -434,6 +462,10 @@ class _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS unique_ptr<_Tp[], _Dp>
   }
 
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __add_lvalue_reference_t<_Tp> operator[](size_t __i) const {
+#ifdef _LIBCPP_ABI_BOUNDED_UNIQUE_PTR
+    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
+        __size_ == 0 || __i < __size_, "unique_ptr<T[]>::operator[](index): index out of range");
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haoNoQ wrote:

If you use `SIZE_MAX` as "unspecified size", will it eliminate the branch? 🤔

https://github.com/llvm/llvm-project/pull/91798