• Jeremy DeHaan (32/32) Dec 27 2015 I was playing around with some code today and I noticed that in
• Adam D. Ruppe (5/7) Dec 27 2015 struct destructors are called when the struct ceases to exist in
• Jeremy DeHaan (3/11) Dec 27 2015 So are these left dangling or do they actually get cleaned up at
• Adam D. Ruppe (9/11) Dec 27 2015 They are left dangling right now. You can clear it yourself by

Jeremy DeHaan <dehaan.jeremiah gmail.com> writes:

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?

Adam D. Ruppe <destructionator gmail.com> writes:

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.

Jeremy DeHaan <dehaan.jeremiah gmail.com> writes:

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?

Adam D. Ruppe <destructionator gmail.com> writes:

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....