Rust

Merge pull request #581 from philipc/issue-580 #798

Job	Run time
features	56s
cross (i686-unknown-linux-gnu)	3m 12s
cross (powerpc64-unknown-linux-gnu)	2m 59s
coverage	2m 16s
build (ubuntu-latest, stable)	2m 25s
doc	23s
build (ubuntu-latest, beta)	2m 44s
msrv-all	6m 3s
msrv-read	4m 39s
build (ubuntu-latest, nightly)	2m 23s
build (stable, macOS-latest)	3m 59s
rustfmt	8s
	32m 7s

Provide feedback