placementnew.cpp

来自「Think in C++ 2nd」· C++ 代码 · 共 29 行

//: C13:PlacementNew.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// Placement with operator new
#include <cstddef> // Size_t
#include <iostream>
using namespace std;

class X {
  int i;
public:
  X(int ii = 0) : i(ii) {}
  ~X() {
    cout << "X::~X()" << endl;
  }
  void* operator new(size_t, void* loc) {
    return loc;
  }
};

int main() {
  int l[10];
  X* xp = new(l) X(47); // X at location l
  xp->X::~X(); // Explicit destructor call
  // ONLY use with placement!
} ///:~