Rob Stewart wrote: ...
That's error-prone. Why not provide (non-zero) capacity when using make_shared(), and leave the non-make_shared() usage with a zero capacity?
That's not very convenient. Suppose you get a T* from some place and need to pass shared_ptr<T[]> to another that requires a known size. You know the size, but you won't be able to pass it. It's also error prone. If you have an interface that takes shared_ptr<T[]> and size_t, you can tell that the code is passing a size by mere visual inspection. But if the function only takes a shared_ptr<T[]>, and if shared_ptr<T[]> might or might not have a size, it's not immediately obvious whether you are passing a size or not. Maybe you are, maybe you aren't; we'll have to wait until runtime and see. Finally, zero is technically a legitimate value for the size, signifying an empty array, so overloading it to denote "unknown" may not be the best option.