Function diff_index_to_worktree 

pub fn diff_index_to_worktree(
    odb: &Odb,
    index: &Index,
    work_tree: &Path,
) -> Result<Vec<DiffEntry>>

Compare the index against the working tree.

This shows “unstaged” changes — modifications not yet staged.

Entries with IndexEntry::assume_unchanged or IndexEntry::skip_worktree are treated as matching the work tree without examining the filesystem (Git CE_VALID / skip-worktree).

Parameters

• odb — object database (for hashing worktree files).
• index — the current index.
• work_tree — path to the working tree root.

Errors

Returns errors from I/O or hashing.