Rollup merge of #57450 - steveklabnik:gh45678, r=KodrAus
Rollup merge of #57450 - steveklabnik:gh45678, r=KodrAus

actually take a slice in this example

Fixes #45678

aidancully/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust