++ Operator one liner

++operator.cpp

#include <iostream>

struct S {
  int value = 0;

  decltype(auto) operator++(auto... t) {
    return ((*this = {value + 1}), ..., S{value - 1 + t});
  }
};

int main() {
  S s;
  std::cout << (s++).value;
  std::cout << s.value;
  std::cout << (++s).value;
  std::cout << s.value;
}