Andre Bogus aabaee0a82 bench and optimize from_slice ...

This adds "bench_from_slice(_vec)(_small)" benches, renaming the previous
versions to "bench_from_iter*" (because they were using `From<&[T]>`, which
calls `FromIterator` internally) and optimizes the `from_slice` constructor
considerably.

Before:
```
test bench_from_slice                  ... bench:          42 ns/iter (+/- 0)
test bench_from_slice_small            ... bench:          12 ns/iter (+/- 0)
```
After:
```
test bench_from_slice                  ... bench:          27 ns/iter (+/- 0)
test bench_from_slice_small            ... bench:           8 ns/iter (+/- 0)
```

2018-08-22 22:14:23 +02:00

..

bench.rs

bench and optimize from_slice

2018-08-22 22:14:23 +02:00