The 3.5e supplement Races of the Wild includes “elvencraft bows,” which are described as
An elvencraft bow is thicker and heavier than a normal bow. An elvencraft shortbow functions as a club when wielded as a melee weapon. An elvencraft longbow functions as a quarterstaff when wielded as a melee weapon.
So an elvencraft shortbow, on some level, is a club as well as it is a shortbow, and since a club is a melee weapon, so is the elvencraft shortbow. Likewise with the elvencraft longbow with respect to being a quarterstaff.
One can, however, make an argument that the bow only “functions as a club when wielded as a melee weapon,” and that when taking ranged attacks, you aren’t wielding it as a ranged weapon, so it doesn’t function as a club, and therefore those ranged attacks aren’t attacks with a melee weapon. However, the counterargument to this is that of course it only “functions” as a club when used as a club—but regardless of how it’s used, it still is a club, since it has the ability to be used as one. This gets to be an almost-philosophical argument about whether a thing’s function is enough to define what that thing is, and ultimately you’ll have to ask with the GM on it.
Going beyond the rules themselves, this makes these projectile weapons rather like thrown weapons, being both melee and ranged. Thrown weapons, for what it’s worth, don’t have any of this “functions as when” nonsense, and are pretty conclusively both melee and ranged weapons regardless of how they are currently used. This can get messy, but having there also be projectile weapons with this property doesn’t especially make things messier.
The 3.5e supplement Tome of Battle includes a “bloodstorm blade” prestige class, which gains the following feature at 2nd:
Thunderous Throw (Ex): [...] As a swift action, you can choose to treat your ranged attack rolls with thrown weapons as melee attacks for the rest of your turn. You use your melee attack bonus, including Strength bonus, feats, and so forth, to determine your attack bonus for each attack as normal, but you apply the standard modifiers for range penalties. Attacking into melee, through cover, and so forth incurs the standard penalties.
This only applies to thrown weapons, but explicitly allows them to be used for “melee attacks,” and not just as “melee weapons.” Maybe this is relevant to you, maybe not, but it seemed worth mentioning.