Miscellaneous C++

C++ Reference

auto_ptr
Syntax:
  #include <memory>
  auto_ptr<class TYPE> name

The auto_ptr class allows the programmer to create pointers that point to other objects. When auto_ptr pointers are destroyed, the objects to which they point are also destroyed.

The auto_ptr class supports normal pointer operations like =, *, and ->, as well as two functions TYPE* get() and TYPE* release(). The get() function returns a pointer to the object that the auto_ptr points to. The release() function acts similarily to the get() function, but also relieves the auto_ptr of its memory destruction duties. When an auto_ptr that has been released goes out of scope, it will not call the destructor of the object that it points to.

Warning: It is generally a bad idea to put auto_ptr objects inside C++ STL containers. C++ containers can do funny things with the data inside them, including frequent reallocation (when being copied, for instance). Since calling the destructor of an auto_ptr object will free up the memory associated with that object, any C++ container reallocation will cause any auto_ptr objects to become invalid.

Example code:
 #include <memory>
 using namespace std;           

 class MyClass {
 public:
   MyClass() {} // nothing
   ~MyClass() {} // nothing
   void myFunc() {} // nothing
 };             

 int main() {
   auto_ptr<MyClass> ptr1(new MyClass), ptr2;             

   ptr2 = ptr1;
   ptr2->myFunc();           

   MyClass* ptr = ptr2.get();           

   ptr->myFunc();            

   return 0;
 }