• Sark7 (25/25) Jun 15 2004 At now auto classes must be declared explicitly to get RAII to work.
• Arcane Jill (5/28) Jun 16 2004 Yeah, that sounds like a bug to me. With a slight modification to the co...
• =?ISO-8859-1?Q?Sigbj=F8rn_Lund_Olsen?= (9/51) Jun 16 2004 " When an auto class reference goes out of scope, the destructor (if

Sark7 <sark7 mail333.com> writes:

At now auto classes must be declared explicitly to get RAII to work.
But implicit declaration can be very useful, like following:

[code]
auto class A
{
   ~this()
   {
     printf("A dtor"\n);
   }
}

void foo(A a) {}

void bar()
{
   foo(new A());
   printf("A out of the scope"\n);
}

void main()
{
   bar();
}
[/code]

Currently I must to declare `auto A a = new A()` in bar() and pass `a` to  
foo(), but it is not good enough for me :)

Besides, default behaviuor seems like a bug, because `new A()` passed to  
foo() in that case is not auto reference; and collected as non-auto class.

Arcane Jill <Arcane_member pathlink.com> writes:

In article <opr9nrzfikut8jae zaitseff.tec.amursk.ru>, Sark7 says...
Besides, default behaviuor seems like a bug, because `new A()` passed to  
foo() in that case is not auto reference; and collected as non-auto class.

Yeah, that sounds like a bug to me. With a slight modification to the code, this
bug becomes stunningly obvious:

auto class A
{
   ~this()
   {
     printf("A dtor"\n);
   }
}

void foo(A a) {}

void bar()
{
   foo(new A());
   printf("A out of the scope"\n);
}

void main()
{
   bar();
   printf("For correct RAII, A should have been deleted BEFORE this point\n");
}

Prints:

A out of the scope
For correct RAII, A should have been deleted BEFORE this point
A dtor

Arcane Jill

=?ISO-8859-1?Q?Sigbj=F8rn_Lund_Olsen?= <sigbjorn lundolsen.net> writes:

Arcane Jill wrote:
 In article <opr9nrzfikut8jae zaitseff.tec.amursk.ru>, Sark7 says...
 
Besides, default behaviuor seems like a bug, because `new A()` passed to  
foo() in that case is not auto reference; and collected as non-auto class.

 
 
 Yeah, that sounds like a bug to me. With a slight modification to the code,
this
 bug becomes stunningly obvious:
 
 
auto class A
{
  ~this()
  {
    printf("A dtor"\n);
  }
}

void foo(A a) {}

void bar()
{
  foo(new A());
  printf("A out of the scope"\n);
}

void main()
{
  bar();
  printf("For correct RAII, A should have been deleted BEFORE this point\n");
}

 
 
 Prints:
 
 
A out of the scope
For correct RAII, A should have been deleted BEFORE this point
A dtor

 
 
 Arcane Jill

" When an auto class reference goes out of scope, the destructor (if 
any) for it is automatically called. This holds true even if the scope 
was exited via a thrown exception."

This really is a showstopping bug, as often you absolutely *must* be 
sure that some resource is released before running subsequent code.

*nudges Walter*

Cheers,
Sigbjørn Lund Olsen