Rollup merge of #39836 - durka:patch-37, r=alexcrichton
Rollup merge of #39836 - durka:patch-37, r=alexcrichton

fix types in to_owned doctest

Fixes #39831.

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