The proposal for shared_ptr<T[N]> has this paragraph:

https://www.open-std.org/JTC1/SC22/WG21/docs/papers/2014/n3920.html

The unfortunate occurence of unique_ptr having lost its support for U[N] obliges me to assert that in shared_ptr case, said support is essentially free, both in terms of implementation complexity or specification complexity. Please don’t remove it. Consider reinstating unique_ptr<U[N]> instead.

Is it simply a case of ‘no-one has since proposed to restore unique_ptr<T[N]>‘, or is there some technical or backwards compatibility reason it can’t be done?

I looked at these two existing questions:

• Why is `make_unique<T[N]>` disallowed?
• Why allow shared_ptr<T[N]>?

The first question was written pre-shared_ptr<T[N]>, and the second considers why shared_ptr<T[N]> was added but not why it wasn’t also added to unique_ptr.