Std::visit is everything wrong with modern C++ (2017)(bitbashing.io)

    xs = [1, 2, 3, 4, 5]
    n = count_if (<3) xs

    xs = // some standard container type, tediously constructed
    n = count_if(xs.begin(), xs.end(), bind2nd(less<int>(), 3))

    type
      MyVarKind = enum mvkNumber, mvkString
      MyVariant = object
        case kind: MyVarKind
        of mvkNumber:
          num: int
        of mvkString:
          str: string

    var myVariant = MyVariant(kind: mvkNumber)
    myVariant.num = 1
    myVariant.str = "Oops"  # Error: 'str' is not accessible using discriminant 'kind' of type 'MyVariant'

    auto [a, b] = functionThatReturnsATuple();

    struct Person {
        std::string name;
        int age;
    };
    Person person = {.name = "Bob", .age = 29};

  std::variant<int, std::string> setting;
  setting = "foo"s;
  setting = 1;

  struct Setting {
    Setting() { XXX }
    ~Setting() { XXX }
    union {
      string str;
      int num;
    };
    enum Type { Str, Int, None };
    Type tag;
  };

  Setting setting;
  if (setting.tag != Setting::Str)
    new (&setting.str) std::string;
  setting.str = "foo";
  setting.tag = Setting::Str;

  if (setting.tag == Setting::Str)
    setting.str.~std::string();
  setting.str = 1;
  setting.tag = Setting::Int;

    if (std::string* s = std::get_if<std::string>(&myVariant)) {
        // Use s
    }
    else if (int* i = std::get_if<std::string>(&myVariant)) {
        // Use i
    }
    else {
        throw std::logic_error("Unexpected type in variant");
    }