====== Void Safety ======

  * [[http://docs.eiffel.com/book/method/void-safe-programming-eiffel|Void Safety Documentation]]
  * {{ :eiffel:meyer-voidsafety.pdf |Ending Null Pointer Crashes}}; Void safety relies on type declarations and static analysis. 
  * {{ :eiffel:faq:avoid-a-void.pdf |Avoid a Void}}

[[https://svn.eecs.yorku.ca/repos/sel-open/misc/tutorial/Void-Safety/Void%20Safety.html|code snippet]]
(login with ''anonymous'' and no password).

===== Slides and Code=====

<code>
svn export https://svn.eecs.yorku.ca/repos/sel-open/misc/tutorial/Void-Safety/node
</code>

[[https://youtu.be/nq3-ZnaLOJs|Slide Video]] 
{{ :eiffel:faq:faq:void-safety.pdf |pdf}}

===== Formal generic type declarations =====


  *FOO [G] = FOO [G -> detachable separate ANY] - actual generic can be detachable and can be separate.
  *FOO [G -> detachable ANY] - actual generic can be detachable, but it is never separate.
  *FOO [G -> ANY] = FOO [G -> attached ANY] - actual generic is always attached and is never separate.
  *FOO [G -> separate ANY] = FOO [G -> attached separate ANY] - actual generic is always attached and can be separate.

It is also possible to have indirect constraints, e.g. BAR [G -> H, H -> ANY] means that actual generic parameter corresponding to G should be attached and non-separate.