类重载operator new/delete,operator new[]/delete[]，全局重载operator new/delete，与原位new将申请内存和构造分离

《C++Primer》（5 th）19.1

#include
using namespace std;

class Foo
{
    public:
        int _id;
    public:
        Foo():_id(0){cout<<"default ctor.this="<

#include 
using namespace std;

class Foo
{
    public:
    Foo(int val = 0):v(val){cout<<"call Foo("<~Foo();         // 析构
    cout<<"---------3--------"<