#include <iostream>
#include <memory>

class test {
int a;
public:
test(int n) : a(n) {}
int get_a() const { return a; }
};

main()
{
const int N = 10;
test* p = static_cast<test*>(::operator new(sizeof(test)*N));

std::uninitialized_fill_n(p, N, 8);

for (int i=0; i<N; ++i) {
std::cout << p[i].get_a() << std::endl;
}
for (int i=0; i<N; ++i) {
p[i].~test();
}
::operator delete(p);
}

>>280
こうなる