Romantic comedies about weddings are the cinematic equivalent of reality shows about wedding planners. They probably reach the exact same audience and involve about the same amount of creative effort. (“Eh, people watch those things. Let’s just make another one of those.”) The Five-Year Engagement has the benefit of a solid cast and a credible bunch of people behind the camera. But it’s still a lazy cut-and-paste job, combining elements of every nuptial-based rom-com since Four Weddings and a Funeral.