CappedString was previously backed by a `[u8; N]`, which required
zeroing the buffer on creation. It now uses a `[MaybeUninit<u8>; N]`,
which does need to be zeroed. This should improve the performance of
creating a new CappedString, at the cost of slightly more unsafe code
required in its implementation.
Additionally, `as_bytes` and `as_bytes_mut` methods were introduced.
These are primarily used internally in the implementation of
CappedString, but are also provided as part of the public API to allow
users to do low-level operations on the underlying buffer backing the
CappedString. `as_bytes_mut` is unsafe, as this method can be used to
violate the UTF-8 property of the CappedString, which is undefined
behaviour.
pantonshire
c8783caae2