No actually its far simpler...A gun can be used as a club...what do you do when its out of ammo? Use it to melee people with it. Its quite effective.
Simple in theory, but how would they build that into the game? That's what I mean by difficult. It seems that NV has very specific weapon types and none of them are hybrids. Guns are guns. Throwing Spears are Throwing Spears. A knife is not the same as a throwing knife.
They would have to create a weapon that looked and functioned like two different weapons. What if you wanted to pistol-whip with a full clip? How would you transition?
I hope this can be managed in future Fallout games, that's for sure. I so badly want to pistol-whip something