Function with

pub fn with(
    user: Option<&ForUser>,
    path: &BStr,
    home_for_user: impl FnOnce(&ForUser) -> Option<PathBuf>,
) -> Result<PathBuf, Error>

Expand path for the given user, which can be obtained by parse(), resolving them with home_for_user(&user).

For the common case consider using [expand_path()] instead.