module Concurrent::SettableStruct

def self.new(*args, &block)
  clazz_name = nil
  if args.length == 0
    raise ArgumentError.new('wrong number of arguments (0 for 1+)')
  elsif args.length > 0 && args.first.is_a?(String)
    clazz_name = args.shift
  end
  FACTORY.define_struct(clazz_name, args, &block)
end

def ==(other)
  synchronize { ns_equality(other) }
end

def [](member)
  synchronize { ns_get(member) }
end

def []=(member, value)
  if member.is_a? Integer
    length = synchronize { @values.length }
    if member >= length
      raise IndexError.new("offset #{member} too large for struct(size:#{length})")
    end
    synchronize do
      unless @values[member].nil?
        raise Concurrent::ImmutabilityError.new('struct member has already been set')
      end
      @values[member] = value
    end
  else
    send("#{member}=", value)
  end
rescue NoMethodError
  raise NameError.new("no member '#{member}' in struct")
end

def each(&block)
  return enum_for(:each) unless block_given?
  synchronize { ns_each(&block) }
end

def each_pair(&block)
  return enum_for(:each_pair) unless block_given?
  synchronize { ns_each_pair(&block) }
end

def inspect
  synchronize { ns_inspect }
end

def merge(other, &block)
  synchronize { ns_merge(other, &block) }
end

def select(&block)
  return enum_for(:select) unless block_given?
  synchronize { ns_select(&block) }
end

def to_h
  synchronize { ns_to_h }
end

def values
  synchronize { ns_values }
end

def values_at(*indexes)
  synchronize { ns_values_at(indexes) }
end