struct MinSize

Array traits:

MinSize is 0 (i.e., admit empty portion of array); take bytes for up to S

instances of T. If |size| > S * MinSize

<T

>(), attempt to evenly distribute

slack bytes amongst T-instance allocations. The purpose of this distribution

is to provide data to variable-sized types that may be stored in the array.

Caveat: When MinSize

<T

>() = 0, attempt to allocate S T-instances.

TODO(https://fxbug.dev/42099318): Consume some input bytes to allocate pseudorandom number of items.