class RuboCop::Cop::Style::RedundantRegexpCharacterClass

def each_single_element_character_class(node)
  node.parsed_tree&.each_expression do |expr|
    next if expr.type != :set || expr.expressions.size != 1
    next if expr.negative?
    next if %i[set posixclass nonposixclass].include?(expr.expressions.first.type)
    yield expr
  end
end