I was playing around with some code today and I noticed that in some cases struct destructors are not called.

for example:

impost std.stdio;

SomeStruct global;

void main()
{
   SomeStruct inMain;
   writeln(global.thing);
   writeln(inMain.thing);
   writeln(getSomeInt());
}

int getSomeInt()
{
    static SomeStruct inner;
    return inner.thing;
}

struct SomeStruct
{
    int thing = 100;
    ~this()
    {
        writeln("destructor");
    }



output is
100
100
100
destructor

Only inMain's destructor is ever called, or at least it is the only one that ever prints "destructor" to the console. Are there special rules for structs that I'm unaware of?

On Sunday, 27 December 2015 at 18:40:55 UTC, Jeremy DeHaan wrote:
> I was playing around with some code today and I noticed that in some cases struct destructors are not called.

struct destructors are called when the struct ceases to exist in the program.

A global variable never ceases to exist as long as the program lives.

On Sunday, 27 December 2015 at 18:47:52 UTC, Adam D. Ruppe wrote:
> On Sunday, 27 December 2015 at 18:40:55 UTC, Jeremy DeHaan wrote:
>> I was playing around with some code today and I noticed that in some cases struct destructors are not called.
>
> struct destructors are called when the struct ceases to exist in the program.
>
> A global variable never ceases to exist as long as the program lives.

So are these left dangling or do they actually get cleaned up at the program exit?

On Sunday, 27 December 2015 at 19:04:11 UTC, Jeremy DeHaan wrote:
> So are these left dangling or do they actually get cleaned up at the program exit?

They are left dangling right now. You can clear it yourself by defining a `static ~this() { .destroy(your struct); }` somewhere in the module.

Maybe that should be done automatically but right now the assumption is those global structs are still available in the static dtors so they are considered alive right up to the program actually exiting... at which point no more code can run since the process has terminated....