How check if destructor has been called?

[Christian Köstlin]

On 13.09.22 19:13, Ben Jones wrote:
> On Tuesday, 13 September 2022 at 14:06:42 UTC, Injeckt wrote:
>> Hi, I'm trying to check if destructor has been called, but when I'm 
>> deleting class object I didn't get any calls from destructor.
>>
>> myclass.d
>>
>>     ~this() {
>>         this.log("\nDestructor\n");
>>         this._free_trash();
>>     }
>>
>>
>> main.d
>>
>>     try {
>>         server.server_init(server);
>>     } catch (Exception e) {
>>         server.log(e.msg);
>>         server = null;
>>     }
> 
> Classes are allocated on the GC heap, so even though you're setting the 
> reference to null, it's not being collected at that point.  You can use 
> `destroy` to make sure the destructor is called (see here: 
> https://dlang.org/spec/class.html#destructors)
> 
> Or you could make your instance `scope` and then it basically follows 
> the same lifetime rules as `struct`s.
Some more things to watch out are mentioned in 
https://p0nce.github.io/d-idioms/#The-trouble-with-class-destructors.

In one of my programs I had problems with allocating in GC called 
destructors (by doing "harmless" writeln debugging).

Kind regards,
Christian