A point that I find missing in the timeline for dynamic array is that there have been implementation for dynamic arrays available in libraries for more than twenty years.
However, none of the authors of those libraries were really happy with their own implementation because those implementations had to choose between performance, API usability or thread safety.
When I closed the student pull request (which was a naive implementation with no unsafe features), it was with the idea that it was unfair to expect a beginner use to solve those issues.
The subsequent iterations explored different part of the design space before the final iteration which converged to safely using unsafe language features to reach a new local API optimum.
However, none of the authors of those libraries were really happy with their own implementation because those implementations had to choose between performance, API usability or thread safety.
When I closed the student pull request (which was a naive implementation with no unsafe features), it was with the idea that it was unfair to expect a beginner use to solve those issues.
The subsequent iterations explored different part of the design space before the final iteration which converged to safely using unsafe language features to reach a new local API optimum.