Function entry_is_dir 

pub fn entry_is_dir(entry: &DirEntry) -> bool

Whether a read_dir entry is a directory, without paying for a stat.

readdir already reports each entry’s own type, so Path::is_dir re-asks the kernel for a fact in hand (measured ~2 µs/entry vs ~14 ns). A symlink’s own type says nothing about its target, and callers have always judged the target, so symlinks fall back to the resolving call.