merging dictionaries in ansible

It is now possible to use the anchor and extend features of YAML:

---
- hosts: localhost
  vars:
    my_default_values: &def
      key: value
    my_values:
      <<: *def
      my_key: my_value
  tasks:
    - debug: var=my_default_values
    - debug: var=my_values

Result:

TASK [debug]
ok: [localhost] => {
    "my_default_values": {
        "key": "value"
    }
}

TASK [debug] 
ok: [localhost] => {
    "my_values": {
        "key": "value", 
        "my_key": "my_value"
    }
}

I have no idea why this was not mentioned before.

In Ansible 2.0, there is a Jinja filter, combine, for this:

- debug: msg="{{ item.key }} = {{ item.value }}"
  with_dict: "{{ my_default_values | combine(my_values) }}"