[libcxx-commits] [libcxx] [libc++] Assert that the position passed to insert and emplace is in [begin(), end()] (PR #230490)

[Ilyas Mallah via libcxx-commits]

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@@ -1243,6 +1243,10 @@ private:
   template <class _BiIter>
   _LIBCPP_HIDE_FROM_ABI iterator __insert_bidirectional(const_iterator __p, _BiIter __f, _BiIter __l, size_type __n);
 
+  _LIBCPP_HIDE_FROM_ABI bool __is_valid_insert_position(const_iterator __p) const {
+    return begin() <= __p && __p <= end();
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ilyas-mallah wrote:

Done in c5af97ea9d. I didn't see the old `<=` misfire, and the change only stops relying on how iterators from different deques compare. The same check would let `deque::erase` verify the iterator belongs to the deque, which #90919 leaves out, and I can do that in a separate PR if it's useful.

https://github.com/llvm/llvm-project/pull/230490