pub unsafe extern "C" fn git_diff_blob_to_buffer(
    old_blob: *const git_blob,
    old_as_path: *const c_char,
    buffer: *const c_char,
    buffer_len: size_t,
    buffer_as_path: *const c_char,
    options: *const git_diff_options,
    file_cb: git_diff_file_cb,
    binary_cb: git_diff_binary_cb,
    hunk_cb: git_diff_hunk_cb,
    line_cb: git_diff_line_cb,
    payload: *mut c_void
) -> c_int