(C++) Pointer

A pointer is a type that holds an address.

When a pointer is uninitialized, it should point to 0 or NULL. You initialize a pointer using the keyword new, which reserves free space for the dynamically allocated instance and returns the address to it.

C++ does not free this memory on its own. Therefore, you have to call delete to do so.

Reading/writing from/to an uninitialized pointer results in an access violation.

Prefer using a smart pointer over a plain pointer [1,2], e.g. use an std::auto_ptr. Use 0 rather than NULL [3]

{
  MyClass * pClass = new MyClass;
  pClass->doStuff();
  delete pClass
}

Using an auto_ptr:

include <memory>


{
  const std::auto_ptr<MyClass> pClass(new MyClass);
  pClass->doStuff(); //Hey, the same way of accessing the pointed instance!
  //Done, std::auto_ptr deletes itself when going out of scope
}

Avoid non-trivial pointer arithmetic [4].

'Pointer' links

general
C

Code links

Reference

1) Scott Meyers. Effective C++ (3rd edition).ISBN: 0-321-33487-6. Item 13: 'Use objects to manage resources'
2) Scott Meyers. Effective C++ (3rd edition).ISBN: 0-321-33487-6. Item 17: 'Store newed objects in smart pointers in standalone statements'
3) Bjarne Stroustrup. The C++ Programming Language (3rd edition).ISBN: 0-201-88954-4 5.8.3: 'Use 0 rather than NULL'.
4) Bjarne Stroustrup. The C++ Programming Language (3rd edition).ISBN: 0-201-88954-4 5.8.1: 'Avoid non-trivial pointer arithmetic'.

last edited (November 8, 2006) by bilderbikkel, Number of views: 5541, Current Rev: 12 (Diff)

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