What are the rules for automatic generation of move operations?

by

Nikos Athanasiou gave a good answer but I wanted to add this tool that I think is very useful.

Here is a screenshot of Howard Hinnant’s presentation “Everything You Ever Wanted To Know About Move Semantics (and then some)” from ACCU 2014 conference which I think is a very good reminder of the rules of automatic generation of special members:

enter image description here

Clarification from Mr Hinnant from the comments:

The slide doesn’t say it, but the red squares indicate deprecated
behavior. I.e. if you don’t want to depend upon deprecated behavior,
then declare both of your copy members if you declare your destructor,
or one of the copy members (basically follow the C++98/03 “rule of 3”)

I recommend reading the slides to get the progressive construction of this table and have a detailed explanation of how and why we have this now.

Other presentations can be found there: http://accu.org/index.php/articles/1901

More Related Contents:

  1. What is move semantics?
  2. How to enforce move semantics when a vector grows?
  3. What is std::move(), and when should it be used?
  4. What can I do with a moved-from object?
  5. When should std::move be used on a function return value? [duplicate]
  6. Reusing a moved container?
  7. Why no default move-assignment/move-constructor?
  8. Move assignment operator and `if (this != &rhs)`
  9. Is a moved-from vector always empty?
  10. Why does std::move prevent RVO (return value optimization)?
  11. Is the pass-by-value-and-then-move construct a bad idiom?
  12. How does std::move() transfer values into RValues?
  13. Does moving leave the object in a usable state?
  14. Is it possible to std::move objects out of functions? (C++11)
  15. Why do we copy then move?
  16. Why do some people use swap for move assignments?
  17. Initializer-list-constructing a vector of noncopyable (but movable) objects
  18. Is a `=default` move constructor equivalent to a member-wise move constructor?
  19. Is an object guaranteed to be moved when it is returned?
  20. Why do you use std::move when you have && in C++11? [duplicate]
  21. Is there any case where a return of a RValue Reference (&&) is useful?
  22. Move or Named Return Value Optimization (NRVO)?
  23. C++11 virtual destructors and auto generation of move special functions
  24. When is explicit move needed for a return statement?
  25. Move out element of std priority_queue in C++11
  26. Should all/most setter functions in C++11 be written as function templates accepting universal references?
  27. C++: std::move with rvalue reference is not moving contents
  28. What is std::move(), and when should it be used and does it actually move anything?
  29. Move semantics == custom swap function obsolete?
  30. Move constructor on derived object

Leave a Comment