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  1. #include <iostream>
  2. #include <fstream>
  3.  
  4. struct record { 
  5.     int a, b;
  6.  
  7.     record(int a=0, int b=0) : a(a), b(b) {}
  8. };
  9.  
  10. std::ostream &operator<<(std::ostream &os, record const &r) { 
  11.     os.write((char *)&r.a, sizeof(r.a));
  12.     os.write((char *)&r.b, sizeof(r.b));
  13.     return os;
  14. }
  15.  
  16. std::istream &operator>>(std::istream &is, record &r) { 
  17.     is.read((char *)&r.a, sizeof(r.a));
  18.     is.read((char *)&r.b, sizeof(r.b));
  19.     return is;
  20. }
  21.  
  22. int main() {
  23.     static const char fname[] = "junk.dat";
  24.  
  25.     std::fstream file(fname, std::ios::in | std::ios::out | std::ios::ate);
  26.  
  27.     if (!file.is_open())
  28.         file.open(fname, std::ios::out);
  29.  
  30.     file << record(1,2);
  31.     file << record(3,4);
  32.     file.seekg(0);
  33.  
  34.     record r;
  35.     file >> r;
  36.  
  37.     std::cout << r.a << ", " << r.b << '\n';
  38.     return 0;
  39. }
  40.  
Not running #stdin #stdout 0s 0KB
comments (?)
stdin 
Standard input is empty
stdout 
Standard output is empty
https://ideone.com/0WIfN
language:
C++ (gcc 8.3)
created:
11 years ago
visibility:
public

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