The (May 2019 Unearthed Arcana) Artificer class gets a feature that works very much like the Extra Attack feature from several existing classes, but with some additional limitations (emphasis added):
Arcane Armament
Starting at 5th level, you can attack twice, rather than once, whenever you take the Attack action on your turn, but one of the attacks must be made with a magic weapon, the magic of which you use to propel the attack.
The requirement to attack with a magic weapon is clear enough, but the final clause highlighted in bold is less clear. Presumably most attacks with magic melee/thrown weapons would not qualify as "magically propelled", but what about magic ranged weapons, like bows and crossbows? Are they propelling their arrows/bolts using magic and therefore eligible for use Arcane Armament? What if the magic weapon doesn't grant a bonus to the attack/damage rolls, but rather has some other effect (e.g. a mundane bow with Arcane Weapon cast on it)? If these would all be eligible for Arcane Armament, is there any ranged magic weapon that wouldn't be eligible?
In essence, what determines or not whether a particular magic weapon uses its magic to propel the attack? Is it just any ranged, non-thrown, magic weapon, or something more complex?