Rust

Fix docstring #7217

Job	Run time
Format + check + test	8m 56s
Check Windows	2m 4s
Check wasm32 + wasm-bindgen	3m 53s
android	35s
cargo-deny aarch64-apple-darwin	53s
cargo-deny aarch64-linux-android	54s
cargo-deny i686-pc-windows-gnu	53s
cargo-deny i686-pc-windows-msvc	52s
cargo-deny i686-unknown-linux-gnu	51s
cargo-deny wasm32-unknown-unknown	52s
cargo-deny x86_64-apple-darwin	3m 29s
cargo-deny x86_64-pc-windows-gnu	52s
cargo-deny x86_64-pc-windows-msvc	50s
cargo-deny x86_64-unknown-linux-gnu	59s
cargo-deny x86_64-unknown-linux-musl	50s
cargo-deny x86_64-unknown-redox	1m 1s
	28m 44s

Provide feedback