A Wednesday puzzler

[xwu (Xiaodi Wu)]

@QuinceyMorris

We only really need Unsafe…BufferPointer because — still at the conceptual level — an Unsafe…Pointer could adequately be represented as a buffer pointer with a count of 1 element.

Usability of pointers in Swift

That's true, but here's a mind bender: why not a buffer pointer with length zero as the default? This actually definitionally does follow the collection semantics, in that it doesn't promise any valid elements. As @Lantua notes, the biggest downside of any of these ideas is that they awkwardly overload subscripting and make that harder. But if we had to make all pointers buffer pointers with default sizes, it seems like the right default size is 0.