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struct alignas(32) Vector {
  char elems[32]; 
};

Vector *f() {
  Vector *pv = new Vector;
  return pv;
}

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In this compliant solution, an overloaded operator new function is defined to obtain appropriately aligned storage by calling the C11 function aligned_alloc(). Programs that make use of the array form of the new expression must define the corresponding member array operator new[] and operator delete[]. The aligned_alloc() function is not part of the C++ 98, C++ 11, or C++ 14 standards but may be provided by implementations of such standards as an extension. Programs targeting C++ implementations that do not provide the C11 aligned_alloc() function must define the member operator new to adjust the alignment of the storage obtained by the allocation function of their choice, either the default global operator new or malloc().

#include <cstdlib>
#include <new>

struct alignas(32) Vector {
  char elems[32];
  static void * operator new(size_t);
  static void operator delete(void *p) {
    free(p);
  }
};

void *Vector::operator new(size_t nbytes) {
 nbytes) {
    if (void *p = std::aligned_alloc(alignof(Vector), nbytes)) {
      return p;
    }
    throw std::bad_alloc();
  }
  static void operator delete(void *p) {
    free(p);
  }
};

Vector *f() {
  Vector *pv = new Vector;
  return pv;
}

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