///Removes duplicate values from `$list`.
///@ignore Documentation: http://sassylists.com/documentation.html#sl-remove-duplicates
///@param {List} $list - list to remove duplicates from
///@requires sl-to-list
///@example
///		sl-remove-duplicates(a b a b)
///		// a b
///@return {List}

@function sl-remove-duplicates($list) {
  @if sl-missing-dependencies(sl-to-list) == true { @return null; }

  $result: ();

  @each $item in $list {
    @if not index($result, $item) {
      $result: append($result, $item, list-separator($list));
    }
  }

  @return sl-to-list($result);
}

///@requires sl-remove-duplicates
///@alias sl-remove-duplicates
 
@function sl-unique($list) {
  @return sl-remove-duplicates($list);
}