??? ??? ??? ??

?? ?????? ?? new ???? ???? ??? ??? ???? ??? ? ????. ??? ??? ?? ???? ??? ???? ??? ?? ??? ??? ???? ?? ???? ?? ??? ?????.

?? ??

new ??? ???? ?? ??? ?? ??? ???? ??? ??? ???? ?? ? ????. ?? C ?? 5.3.4? Note 12? ???? ????. ?????, ??? ??? ??? ???? ?? ??? ???.

?? ?? ??????.

#include <iostream>
#include <new>

class A {
public:
    A() : data(0) {}
    ~A() {}
    int data;
};

int main() {
    const int NUMELEMENTS = 20;

    char *pBuffer = new char[NUMELEMENTS * sizeof(A)];
    A *pA = new(pBuffer) A[NUMELEMENTS];

    // Output may show pA as four bytes higher than pBuffer
    std::cout << "Buffer address: " << pBuffer << ", Array address: " << pA << std::endl;

    delete[] pBuffer;

    return 0;
}

? ?? Microsoft Visual Studio?? ??? ??? ???? ??? ????. ???? ??? ?? ????? ?? ?? ?? 4???? ???? ?? ?? ?? ??? ???? ??? ? ? ????. ? ??? ??? ????? ???? ?? ????.

?? ??? ???

? ??? ??? ????? ??? ?? ?? new? ???? ????. ?? ??? ??? ???? ??? ? ??? ????? ???? ?? ????.

#include <iostream>
#include <new>

class A {
public:
    A() : data(0) {}
    ~A() {}
    int data;
};

int main() {
    const int NUMELEMENTS = 20;

    char *pBuffer = new char[NUMELEMENTS * sizeof(A)];
    A *pA = (A*)pBuffer;

    for (int i = 0; i < NUMELEMENTS; ++i) {
        pA[i] = new (pA + i) A();
    }

    std::cout << "Buffer address: " << pBuffer << ", Array address: " << pA << std::endl;

    // Remember to manually destroy each element
    for (int i = 0; i < NUMELEMENTS; ++i) {
        pA[i].~A();
    }

    delete[] pBuffer;

    return 0;
}

?? ?? ??? ???? ??? ???? ?? ? ?? ??? ???? ???? ?? ??? ??? ???? ? ?????.

? ??? C ?? ???? ??? ?? ??? ??????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!