This is an alternative to `Extend::extend` method for cases where the
length of the iterator can not be checked. Since this vector can not
reallocate to increase its capacity, it is unclear what to do with
remaining elements in the iterator and the iterator itself. The
interface also provides no way to communicate this to the caller.
Avoids a call to Clone of the element by using the provided instance as
the one inserted last. A similar optimization is used in the standard
library. Also changes the iteration to an independent iterator as the
number of insert elements must be known in advance.
This makes the code more readable by shortening lines and avoid explicit
or redundant type annotations. The core function would require a rust
version of 1.40 so straightforward implementation is added to the crate.
The new slice is already initialized with default values for T due to
the constructor used. Instead of using different defaulted values for
replacing the split-off instances we can simply swap slices. This
reduces pressure on the optimizer and uses a probably optimized method
from the core library.
Lokathor