Apenas como uma arma improvisada.
De a descrição de Armas Improvisadas (também no Regras básicas ou PHB p. 147-148):
Improvised Weapons
Sometimes characters don’t have their weapons and have to attack with whatever is close at hand. An improvised weapon includes any object you can wield in one or two hands, such as broken glass, a table leg, a frying pan, a wagon wheel, or a dead goblin.
In many cases, an improvised weapon is similar to an actual weapon and can be treated as such. For example, a table leg is akin to a club. At the DM’s option, a character proficient with a weapon can use a similar object as if it were that weapon and use his or her proficiency bonus.
An object that bears no resemblance to a weapon deals 1d4 damage (the DM assigns a damage type appropriate to the object). If a character uses a ranged weapon to make a melee attack, or throws a melee weapon that does not have the thrown property, it also deals 1d4 damage. An improvised thrown weapon has a normal range of 20 feet and a long range of 60 feet.
Conselhos adicionais de Sage que suportam isso via Twitter :
Parece claro que a intenção é que qualquer uso de uma arma de longo alcance para fazer um ataque corpo a corpo (ou seja, acertá-los com a arma em si) envolveria sua arma de longo alcance sendo tratada como uma arma improvisada, então o ataque seguiria a arma. regras para armas improvisadas.If you use a weapon in a way contrary to its design (melee attack w/ a ranged weapon), see "Improvised Weapons" (PH, 147). DM's call. [...] If you turn the page, you'll see the standard thing to do with a ranged weapon being used as a melee weapon.