# Is there exists a Dart dynamic type equivalent for Crystal? (Or, equivalent usage)

**URL:** <https://forum.crystal-lang.org/t/is-there-exists-a-dart-dynamic-type-equivalent-for-crystal-or-equivalent-usage/5082>\
**Category:** Help & Support\
**Created:** [November 5, 2022, 2:21pm UTC](https://forum.crystal-lang.org/t/is-there-exists-a-dart-dynamic-type-equivalent-for-crystal-or-equivalent-usage/5082 "2022-11-05T14:21:39Z")\
**Posts on this page:** 1\
**Showing post:** 8

<div class="post-metadata">

**Author:** ![asterite](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.crystal-lang.org/asterite/32/60_2.png) [@asterite](https://forum.crystal-lang.org/u/asterite)\
**Post date:** [November 5, 2022, 6:33pm UTC](https://forum.crystal-lang.org/t/is-there-exists-a-dart-dynamic-type-equivalent-for-crystal-or-equivalent-usage/5082/8 "2022-11-05T18:33:07Z")

</div>

I guess you can do this?

```crystal
class BlackHole
  macro method_missing(call)
    raise "BUG: must implement {{call.name}}"
  end
end

array = BlackHole.new
array << 1
array << "hello"
puts array.size
array.each do |x|
  puts x
end

```

Such type will never make it to the standard library, though.

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