fork(4) download 
  1. #include <iostream>
  2.  
  3. template<typename T>
  4. class Deleter
  5. {
  6.         T x;
  7. public:
  8.         inline Deleter( const T functor ): x(functor) { };
  9.         inline ~Deleter() { x(); };
  10. };
  11.  
  12. template<typename T>
  13. inline Deleter<T> finally( const T x )
  14. {
  15.         return Deleter<T>(x);
  16. };
  17.  
  18. #define FINALLY_IMPL(line, code) auto deleter##line = finally( [&]() { code; } );
  19. #define FINALLY(code) FINALLY_IMPL(__LINE__, code)
  20.  
  21. class Test
  22. {
  23. private:
  24.         int code;
  25. public:
  26.         Test(int c): code(c) { std::cout << "Test(" << code << ");\n"; };
  27.         ~Test() { std::cout << "~Test(" << code << ");\n"; };
  28.         void method() { std::cout << "method(" << code << ")\n"; };
  29. };
  30.  
  31. void func()
  32. {
  33.         Test *x = nullptr;
  34.         FINALLY(
  35.                 delete x;
  36.         );
  37.  
  38.         {
  39.                 Test *y = nullptr;
  40.                 FINALLY(
  41.                         delete y;
  42.                 );
  43.                 y = new Test(1);
  44.                 y->method();
  45.         };
  46.         x = new Test(2);
  47.         x->method();
  48. };
  49.  
  50. int main(int argc, char *argv[]) 
  51. {
  52.         func();
  53.         std::cout << "ok\n";
  54.         return 0;
  55. }
Success #stdin #stdout 0s 3272KB
comments (?)
stdin 
Standard input is empty
stdout 
Test(1);
method(1)
~Test(1);
Test(2);
method(2)
~Test(2);
ok
https://ideone.com/qqdSyf
language:
C++14 (gcc 8.3)
created:
10 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!