The "@safe vs struct destructor" dilemma

[Michel Fortin]

On 2014-04-11 19:54:16 +0000, Michel Fortin <michel.fortin at michelf.ca> said:

> Can destructors be @safe at all? When called from the GC the destructor 
> 1) likely runs in a different thread and 2) can potentially access 
> other destructed objects, those objects might contain pointers to 
> deallocated memory if their destructor manually freed a memory block.

There's another issue I forgot to mention earlier: the destructor could 
leak the pointer to an external variable. Then you'll have a reference 
to a deallocated memory block.

Note that making the destructor pure will only helps for the global 
variable case. The struct/class itself could contain a pointer to a 
global or to another memory block that'll persist beyond the 
destruction of the object and assign the pointer there. It can thus 
leak the deallocating object (or even "this" if it's a class) through 
that pointer.

-- 
Michel Fortin
michel.fortin at michelf.ca
http://michelf.ca