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  1. #include <iostream>
  2.  
  3. //#include <xmmintrin.h>
  4. typedef float __m128 __attribute__ ((vector_size (16)));
  5.  
  6.  
  7. class A {
  8. public:
  9.    long double a;
  10.    __m128 m; 
  11.    long long b;
  12.    A() : a(1.3), b(123) {}
  13. };
  14.  
  15. char buffer[64];
  16.  
  17. template <class T>
  18. struct BA {
  19.    char a[sizeof(T)]; 
  20.    bool taken;
  21.    BA* next;
  22. }__attribute__ ((aligned(__alignof(T))));
  23.  
  24. int main() {
  25.    A* a = new (buffer + 1) A();
  26. #define PRINTT(a) std::cout << #a ": " << a  << std::endl;
  27.    PRINTT((void*)a);
  28.    PRINTT((void*)(buffer + 1));
  29.    PRINTT(sizeof(A));
  30.    PRINTT(__alignof(A));
  31.    if (__alignof(A) > 0) 
  32.       PRINTT(size_t(buffer + 1) % __alignof(A));
  33.    PRINTT(a->a);
  34.    PRINTT(a->b);
  35.  
  36.    A b = *a;
  37.    PRINTT(b.a);
  38.    PRINTT(b.b);
  39.  
  40.    a->~A();
  41.  
  42.   PRINTT(__alignof(char));
  43.   PRINTT(__alignof(int));
  44.   PRINTT(__alignof(int*));
  45.   PRINTT(__alignof(int (A::*)()));
  46.   PRINTT(__alignof(long double));
  47.   PRINTT(__alignof(long long));
  48.   PRINTT(sizeof(BA<A>));
  49.   PRINTT(__alignof(BA<A>));
  50.   PRINTT(offsetof(BA<A>,a));
  51.   PRINTT(offsetof(BA<A>,taken));
  52.   PRINTT(offsetof(BA<A>,next));
  53. }
Success #stdin #stdout 0.01s 2728KB
comments (?)
stdin 
Standard input is empty
stdout 
(void*)a: 0x804b101
(void*)(buffer + 1): 0x804b101
sizeof(A): 48
__alignof(A): 16
size_t(buffer + 1) % __alignof(A): 1
a->a: 1.3
a->b: 123
b.a: 1.3
b.b: 123
__alignof(char): 1
__alignof(int): 4
__alignof(int*): 4
__alignof(int (A::*)()): 4
__alignof(long double): 4
__alignof(long long): 8
sizeof(BA<A>): 64
__alignof(BA<A>): 16
offsetof(BA<A>,a): 0
offsetof(BA<A>,taken): 48
offsetof(BA<A>,next): 52
https://ideone.com/jBrk8
language:
C++ (gcc 8.3)
created:
12 years ago
visibility:
secret

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