Function copy_into_dir 

pub fn copy_into_dir(
    src: &Path,
    dir: &Path,
    name: &str,
    ctl: &CopyControl<'_>,
) -> Result<PathBuf>

Copy src (a file, or a folder recursively) into dir under name made valid by copy_name and de-conflicted. Returns the path it landed at. Symlinks inside a copied folder are skipped, so a link loop can’t recurse. On error or cancel nothing is left behind.