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  1. #include <stdio.h>
  2.  
  3. class A {
  4. public:
  5.     A() { a = 0; printf("A()\n"); }
  6.  
  7.     int a;
  8. };
  9.  
  10. class B : virtual public A {
  11. };
  12.  
  13. class C : public B {
  14. public:
  15.     C() {}
  16.     C(const C &from) : B(from) {}
  17. };
  18.  
  19. template<typename T>
  20. void
  21. test() {
  22.     T t1;
  23.     t1.a = 3;
  24.     printf("pre-copy\n");
  25.     T t2(t1);
  26.     printf("post-copy\n");
  27.     printf("t1.a=%d\n", t1.a);
  28.     printf("t2.a=%d\n", t2.a);
  29. }
  30.  
  31. int
  32. main() {
  33.     printf("B:\n");
  34.     test<B>();
  35.  
  36.     printf("\n");
  37.  
  38.     printf("C:\n");
  39.     test<C>();
  40. }
Success #stdin #stdout 0s 3412KB
comments (?)
stdin
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Standard input is empty
stdout
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B:
A()
pre-copy
post-copy
t1.a=3
t2.a=3

C:
A()
pre-copy
A()
post-copy
t1.a=3
t2.a=0
https://ideone.com/Eeupgk
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
public

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