What if review: That’s some bad hat, Harry

It is sobering to consider that, in its quieter moments, this perfectly serviceable romantic comedy thinks itself to be journeying towards unchartered territories. In fact, the indie-flavoured rom-com is now so familiar as to have taken on industrial status. The slightly awkward couple live in some attractive Bohemian locale and spent most of their time exchanging trivia that, if honed, could form the basis for a stand-up comedy routine. Their friends are that little bit odder. Meeting cute leads to months of living cuter. (500) Days of Summer is the exemplar of the genre: a school of film-making that tries to make unthreatening outsiders of us all.

What If follows these unconventional conventions with some flair. It helps that two charming young actors play the chief romancers. Daniel Radcliffe still wears the demeanour of a habitual good boy who, after one uncharacteristic indiscretion, finds himself waiting outside the headmaster's office. Zoe Kazan has that cartoon koala look down perfectly. Only a monster would hope for anything other than their eventual happy union.

This is the one about the couple who, though obviously ideally suited, try to pretend they’re just good friends. An Irish-Canadian co-production starring an Englishman and a Californian, the picture spends most of its time about prettier corners of Toronto. Wallace (I know) and Chantry (I know!) meet before the fridge magnets at a party and fall into deep friendship. Unfortunately, Chantry remains attached to square (Ralph Spall) who works at the UN.

Scored to inevitable strummy folk-pop, the film keeps itself amusingly busy until Wall and Chan do what it is they are going to do. A running gag about Elvis’s diet fleshes out the emptier moments. There are some bearable animated whimsies.

Domestic viewers may find themselves puzzled by one peculiar inconsistency. When Spall’s character travels to Dublin we are informed (twice) that he is living on Camden St, Dublin 2. His house is, however, clearly situated somewhere more leafy and suburban. It doesn’t matter much, but why get it wrong when it costs nothing to get it right?