The permanent (version-specific) link to the to_str method of PathBuf in the Rust standard library documentation is constructed by including the version number in the URL. The general format is:

https://doc.rust-lang.org/{version}/std/path/struct.PathBuf.html#method.to_str

For example, for Rust 1.70.0, the link would be: https://doc.rust-lang.org/1.70.0/std/path/struct.PathBuf.html#method.to_str

To get the latest stable version, replace {version} with the desired Rust version (e.g., stable, 1.75.0, etc.). If you want the absolute latest stable version, you can use: https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#method.to_str