doubler = (o) =>
    o.valeur *= 2
tripler = (o) =>
    o.valeur *= 3
quadrupler = (o) =>
    o.valeur *= 4
quintupler = (o) =>
    o.valeur *= 5
sextupler = (o) =>
    o.valeur *= 6
octupler = (o) =>
    o.valeur *= 8
décupler = (o) =>
    o.valeur *= 10
centupler = (o) =>
    o.valeur *= 100