超小ネタ: Goでif式をやりてんじゃ。

    queryParam := c.QueryParam("queryParam")
    param, err := func() (int, error) {
        if queryParam == "" {
            return defaultValue, nil
        }
        return strconv.Atoi(queryParam) //Atoiは結果とerrorの2値を返す
    }()

    queryParam := c.QueryParam("queryParam")
    var param int
    var err error
    if queryParam == "" {
        param = defaultValue
    } else {
        param, err = strconv.Atoi(queryParam)
    }