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digitalmars.D.learn - Throwing constructors and member destructors

reply Boris-Barboris <ismailsiege gmail.com> writes:
https://run.dlang.io/is/LdylJX

Notice no "B destructor" line in stdout.

Just got bitten by the assumption that my Buffer struct that 
transactionally aquires multiple external resources in 
constructor will rollback via member destructors that were 
successfully completed before the throw.

Can I get a clarification about current semantics? Should I 
essentially never throw in constructors if I want to rely on 
scope-based RAII?

And before we start a 10-page argument about the ideology of 
constructors, I would mostly just like to hear that this is 
documented somewhere, because I have certanly missed it.
Nov 20 2018
next sibling parent Alex <sascha.orlov gmail.com> writes:
On Tuesday, 20 November 2018 at 13:01:40 UTC, Boris-Barboris 
wrote:

 https://run.dlang.io/is/LdylJX

 Notice no "B destructor" line in stdout.

 Just got bitten by the assumption that my Buffer struct that 
 transactionally aquires multiple external resources in 
 constructor will rollback via member destructors that were 
 successfully completed before the throw.

 Can I get a clarification about current semantics? Should I 
 essentially never throw in constructors if I want to rely on 
 scope-based RAII?

 And before we start a 10-page argument about the ideology of 
 constructors, I would mostly just like to hear that this is 
 documented somewhere, because I have certanly missed it.


For example:

https://books.google.de/books?id=5_eoCwAAQBAJ&pg=PA104&lpg=PA104&dq=dlang+rely+destructor&source=bl&ots=p33jiNUKBq&sig=yw1ymCzaRaueQ8yDDMjP75iRDYI&hl=de&sa=X&ved=2ahUKEwjosrGlhePeAhVrgM4BHcU6DEAQ6AEwBXoECAMQAQ#v=onepage&q=dlang%20rely%20destructor&f=false

 book{parker2015learning,
   title={Learning D},
   author={Parker, M.},
   isbn={9781785289347},
   url={https://books.google.de/books?id=5\_eoCwAAQBAJ},
   year={2015},
   publisher={Packt Publishing}
   page=104
}

But yeah... I had troubles to find such a clear statement on 
dlang.org too...
Nov 20 2018
prev sibling parent reply Stanislav Blinov <stanislav.blinov gmail.com> writes:
On Tuesday, 20 November 2018 at 13:01:40 UTC, Boris-Barboris 
wrote:

 https://run.dlang.io/is/LdylJX

 Notice no "B destructor" line in stdout.

 Just got bitten by the assumption that my Buffer struct that 
 transactionally aquires multiple external resources in 
 constructor will rollback via member destructors that were 
 successfully completed before the throw.

 Can I get a clarification about current semantics? Should I 
 essentially never throw in constructors if I want to rely on 
 scope-based RAII?

 And before we start a 10-page argument about the ideology of 
 constructors, I would mostly just like to hear that this is 
 documented somewhere, because I have certanly missed it.


https://dlang.org/changelog/2.083.0.html#reboot14246
Nov 20 2018
next sibling parent Boris-Barboris <ismailsiege gmail.com> writes:
On Tuesday, 20 November 2018 at 13:20:08 UTC, Stanislav Blinov 
wrote:

 https://dlang.org/changelog/2.083.0.html#reboot14246


Wording "object" means both classes and structs?
Nov 20 2018
prev sibling parent reply Boris-Barboris <ismailsiege gmail.com> writes:
On Tuesday, 20 November 2018 at 13:20:08 UTC, Stanislav Blinov 
wrote:

 https://dlang.org/changelog/2.083.0.html#reboot14246


Nvm, found the info in the issue tracker, thank you for the link.
Nov 20 2018
parent Stanislav Blinov <stanislav.blinov gmail.com> writes:
On Tuesday, 20 November 2018 at 13:28:21 UTC, Boris-Barboris 
wrote:

 On Tuesday, 20 November 2018 at 13:20:08 UTC, Stanislav Blinov 
 wrote:

 https://dlang.org/changelog/2.083.0.html#reboot14246


 Nvm, found the info in the issue tracker, thank you for the 
 link.


You're welcome. It's one of those problems that were out there 
for ages, and luckily it now is getting attention.
Nov 20 2018