doctrine/doctrine2 — pull request #1122 by Ocramius (2014-08-26 23:59:29+00:00)
Title: Support arithmetic expressions in `COUNT()`

tl;dr:

Following is now allowed

```sql
SELECT COUNT(DISTINCT CONCAT(u.name, u.surname)) FROM User u
```

I am not aware of RDBMS implementations that do not support this. Ping @guilhermeblanco