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Zig std.ArrayList gains lockPointers and unlockPointers to panic on invalidated element pointers during growth
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Zig's standard library now supports pointer stability locks on ArrayList, letting developers detect when stored pointers to elements are invalidated by reallocation.
Without this, storing pointers into an ArrayList's backing memory and then growing the list causes silent memory corruption that is difficult to debug. With lockPointers, the program panics with a stack trace at the point of violation instead, making the bug immediately visible.
Written by elseif from the cluster below · every claim links back to a sourceThe three things worth knowing
Pointer Stability Locks, previously available for std Hash Map containers since 2024, now extend to std.ArrayList via a pull request originally opened by Leo Emar-Kar in 2025.
Developers call lockPointers() when storing pointers to ArrayList elements and unlockPointers() when those pointers are no longer needed.
If the ArrayList needs to grow while pointers are locked, the program panics with a stack trace rather than silently corrupting memory.
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