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// operator new example
#include <iostream> // std::cout
#include <new> // ::operator new
struct MyClass {
int data[100];
MyClass() {std::cout << "constructed [" << this << "]\n";}
};
int main () {
std::cout << "1: ";
MyClass * p1 = new MyClass;
// allocates memory by calling: operator new (sizeof(MyClass))
// and then constructs an object at the newly allocated space
std::cout << "2: ";
MyClass * p2 = new (std::nothrow) MyClass;
// allocates memory by calling: operator new (sizeof(MyClass),std::nothrow)
// and then constructs an object at the newly allocated space
std::cout << "3: ";
new (p2) MyClass;
// does not allocate memory -- calls: operator new (sizeof(MyClass),p2)
// but constructs an object at p2
// Notice though that calling this function directly does not construct an object:
std::cout << "4: ";
MyClass * p3 = (MyClass*) ::operator new (sizeof(MyClass));
// allocates memory by calling: operator new (sizeof(MyClass))
// but does not call MyClass's constructor
delete p1;
delete p2;
delete p3;
return 0;
}
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