{ lib }:
let
  overlayPath = ./.;
  candidates = lib.attrNames (builtins.readDir overlayPath);
  pathToOverlay = n: overlayPath + ("/" + n);
  isNixFile = n: builtins.match ".*\\.nix" n != null;
  isNixDir = n: builtins.pathExists (pathToOverlay n + "/default.nix");
  notDefault = n: n != "default.nix";
  isOverlay = n: (isNixDir n || isNixFile n) && notDefault n;
  overlays = builtins.filter isOverlay candidates;
  importOverlay = n: import (pathToOverlay n);
in
map importOverlay overlays