fix miri #81

Job	Run time
docs	16s
cross (aarch64-unknown-linux-gnu)	1m 13s
clippy (ubuntu-latest)	18s
build (ubuntu-latest)	14s
cross (aarch64-linux-android)	1m 30s
clippy (macos-latest)	21s
build (macos-latest)	15s
miri (ubuntu-latest)	9m 12s
cross (aarch64-unknown-linux-musl)	1m 16s
clippy (windows-latest)	1m 13s
build (windows-latest)	1m 8s
miri (macos-latest)	8m 32s
cross (i686-linux-android)	1m 26s
miri (windows-latest)	19s
cross (x86_64-linux-android)	1m 23s
rustfmt (ubuntu-latest)	11s
cross (i686-pc-windows-gnu)	1m 40s
sanitizer (ubuntu-latest)	13s
test (ubuntu-latest)	52s
rustfmt (macos-latest)	18s
cross (x86_64-pc-windows-gnu)	1m 38s
sanitizer (macos-latest)	18s
test (macos-latest)	31s
rustfmt (windows-latest)	41s
cross (i686-unknown-linux-gnu)	1m 14s
sanitizer (windows-latest)	20s
test (windows-latest)	54s
cross (powerpc64-unknown-linux-gnu)	1m 19s
cross (riscv64gc-unknown-linux-gnu)	1m 6s
cross (wasm32-unknown-unknown)	14s
cross (wasm32-unknown-emscripten)	1m 21s
coverage	0s
	41m 26s

Provide feedback