[libcxx-commits] [libcxx] [libc++][Docs] Document `std::optional` hardening (PR #218173)

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llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libcxx

Author: William Tran-Viet (smallp-o-p)

<details>
<summary>Changes</summary>

Resolves #<!-- -->218041 

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Full diff: https://github.com/llvm/llvm-project/pull/218173.diff


1 Files Affected:

- (modified) libcxx/docs/Hardening.rst (+6) 


``````````diff
diff --git a/libcxx/docs/Hardening.rst b/libcxx/docs/Hardening.rst
index 1360518379aef..0237a0e73aba0 100644
--- a/libcxx/docs/Hardening.rst
+++ b/libcxx/docs/Hardening.rst
@@ -440,6 +440,12 @@ CMake configuration time. The available options are:
 
   ABI impact: changes the iterator type of ``std::array``, its size and its layout.
 
+- ``_LIBCPP_ABI_BOUNDED_ITERATORS_IN_OPTIONAL`` -- changes the iterator type of ``std::optional`` to a
+  bounded iterator that keeps track of whether it's within the bounds of its container and asserts it
+  on every dereference and when performing iterator arithmetic.
+
+  ABI impact: changes the iterator type of ``std::optional``.
+
 ABI tags
 --------
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/218173