Why is a static struct's dtor called at the exit of a function?

[Steven Schveighoffer]

On Wed, 20 Jul 2011 15:57:44 -0400, Jonathan M Davis <jmdavisProg at gmx.com>  
wrote:

> On Wednesday 20 July 2011 21:54:19 Andrej Mitrovic wrote:
>> import std.stdio;
>>
>> void main()
>> {
>>     writeln("test");
>>     test();
>>     writeln();
>>     writeln("test");
>>     test();
>> }
>>
>> struct Foo
>> {
>>     int state;
>>     this (int i)
>>     {
>>         state = i;
>>     }
>>
>>     ~this()
>>     {
>>         writeln("dtor");
>>     }
>> }
>>
>> void test()
>> {
>>     static Foo foo = Foo(1);
>>     writeln(foo.state);
>> }
>>
>> Prints:
>> test
>> 1
>> dtor
>>
>> test
>> 1
>> dtor
>>
>> Shouldn't static variables be left untouched? I tried to use a struct
>> to handle an external device context, however the dtor would be kept
>> called between function calls, so this caused crashes for me.
>>
>> Using a class instead fixes my issue of course.
>>
>> I thought "static" for variables implied it has lifetime until the end
>> of the application, regardless of whether the memory for the variable
>> was allocated on the heap or is in the .data segment or somewhere
>> else.
>
> static variables are supposed to have essentially the same lifetime as  
> the
> program. So, it definitely looks like a bug.

slight correction -- static variables are thread local (must be marked  
shared to be shared between threads), so the destructor should be called  
on Thread destruction.

However, I don't think that any destructors are called on thread  
destruction...

But yes, they should *definitely* not be called on function exit.  This is  
a bug.

-Steve