fork(1) download
copy 
  1. #include <array>
  2. #include <cstring>
  3. #include <iostream>
  4.  
  5. struct Oops {
  6.     char a;
  7.     int b;
  8. };
  9.  
  10. void foo(std::array<char, 8>&) {
  11. }
  12. void (*foo_ptr)(std::array<char, 8>&) = foo;
  13.  
  14. bool __attribute__((noinline)) bar(Oops& o, char a, int b) {
  15.     union {
  16.         std::array<char, 8> x;
  17.         Oops y;
  18.     };
  19.     x = {'P', 'o', 'p', 'a', 'p', 'o', 'p', 'a'};
  20.     foo_ptr(x);
  21.     y = {a, b};
  22.     return std::memcmp(&o, &y, sizeof y) == 0;
  23. }
  24.  
  25. int main() {
  26.     Oops a = {1, 2};
  27.     if (bar(a, 1, 2)) {
  28.         std::cout << "Everything's fine" << std::endl;
  29.     } else {
  30.         std::cout << "Someone's an idiot" << std::endl;
  31.     }
  32. }
Success #stdin #stdout 0s 4476KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Someone's an idiot
https://ideone.com/6wJhE8
language:
C++ (gcc 8.3)
created:
4 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!