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(C++) pointer

A pointer is a type that holds an address.

A pointer can be initialized with 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.

Advice

• Keep use of pointers simple and straightforward [6]
• Initialize a pointer with nullptr [8] (in C++11) or the integer literal 0 [4] (in C++98), rather than NULL.
• Avoid non-trivial pointer arithmetic [5,7]
• Prefer using a smart pointer over a plain pointer [1-3]
• Keep pointers that represent ownership inside handle classes [9-11]
• Use const pointers to express immutability in interfaces [13]
• Prefer references to pointers as arguments, except where "no object" is a reasonable option [14,15]
• Avoid void* except in low-level code [12]

References

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. Herb Sutter, Andrei Alexandrescu. C++ coding standards: 101 rules, guidelines, and best practices. 2005. ISBN: 0-32-111358-6. Chapter 13: 'Ensure resources are owned by objects. Use explicit RAII and smart pointers.
4. Bjarne Stroustrup. The C++ Programming Language (3rd edition). 1997. ISBN: 0-201-88954-4. Section 5.8.3: 'Use 0 rather than NULL'.
5. Bjarne Stroustrup. The C++ Programming Language (3rd edition). 1997. ISBN: 0-201-88954-4. Section 5.8.1: 'Avoid non-trivial pointer arithmetic'.
6. Bjarne Stroustrup. The C++ Programming Language (4th edition). 2013. ISBN: 978-0-321-56384-2. Chapter 7.8. Advice, page 199: '[1] Keep use of pointers simple and straightforward'
7. Bjarne Stroustrup. The C++ Programming Language (4th edition). 2013. ISBN: 978-0-321-56384-2. Chapter 7.8. Advice, page 199: '[2] Avoid nontrivial pointer arithmetic'
8. Bjarne Stroustrup. The C++ Programming Language (4th edition). 2013. ISBN: 978-0-321-56384-2. Chapter 7.8. Advice, page 199: '[5] Use nullptr rather than 0 or NULL'
9. Bjarne Stroustrup. The C++ Programming Language (4th edition). 2013. ISBN: 978-0-321-56384-2. Chapter 7.8. Advice, page 199: '[11] Keep pointers that represent ownership inside handle classes'
10. Scott Meyers. Effective C++ (3rd edition). ISBN: 0-321-33487-6. Item 13: 'Use objects to manage resources'.
11. Herb Sutter, Andrei Alexandrescu. C++ coding standards: 101 rules, guidelines, and best practices. 2005. ISBN: 0-32-111358-6. Chapter 13: 'Ensure resources are owned by objects. Use explicit RAII and smart pointers.
12. Bjarne Stroustrup. The C++ Programming Language (4th edition). 2013. ISBN: 978-0-321-56384-2. Chapter 7.8. Advice, page 199: 'Avoid void* except in low-level code'
13. Bjarne Stroustrup. The C++ Programming Language (4th edition). 2013. ISBN: 978-0-321-56384-2. Chapter 7.8. Advice. page 199: '[13] Use const pointers and const references to express immutability in interfaces'
14. Bjarne Stroustrup. The C++ Programming Language (4th edition). 2013. ISBN: 978-0-321-56384-2. Chapter 7.8. Advice. page 199: '[14] Prefer references to pointers as arguments, except where "no object" is a reasonable option'
15. Bjarne Stroustrup. The C++ Programming Language (4th edition). 2013. ISBN: 978-0-321-56384-2. Chapter 12.7. Advice. page 341: '[11] Pass a pointer if "no object" is a valid alternative (and represent "no object" by nullptr)'

Go back to Richel Bilderbeek's C++ page.

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