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digitalmars.D - std.variant holding bigger structs and std.concurrency message

reply "Tavi Cacina" <octavian.cacina outlook.com> writes:
is it a bug the fact that a Variant may be initialized with a 
struct bigger than 32 bytes? Even if this does function, it is 
not consistent because you can not assign such an 'inflated' 
variant to another one, assertion. This affects the max size of a 
std.concurrency message (right now it is not specified that such 
restriction exists)

---
import std.variant;

struct S
{
   int[9] s;
}

void main()
{
   Variant v1, v2; // maximum size 32 bytes
   v1 = S(); // works, even if sizeof(S) > 32
   v2 = v1; // AssertError: target must be non-null
}
---
Apr 27 2013
parent reply "Idan Arye" <GenericNPC gmail.com> writes:
On Saturday, 27 April 2013 at 11:37:38 UTC, Tavi Cacina wrote:

 is it a bug the fact that a Variant may be initialized with a 
 struct bigger than 32 bytes? Even if this does function, it is 
 not consistent because you can not assign such an 'inflated' 
 variant to another one, assertion. This affects the max size of 
 a std.concurrency message (right now it is not specified that 
 such restriction exists)

 ---
 import std.variant;

 struct S
 {
   int[9] s;
 }

 void main()
 {
   Variant v1, v2; // maximum size 32 bytes
   v1 = S(); // works, even if sizeof(S) > 32
   v2 = v1; // AssertError: target must be non-null
 }
 ---


There used to be a maximum size check for placing things in 
variants, but it was removed back in 2009: 
https://github.com/D-Programming-Language/phobos/commit/0c142994d9b5cb9f379eca28f3a625c749370e4a#L20L189

The way it works now, is that if the size is too big they use a 
reference instead: 
https://github.com/D-Programming-Language/phobos/blob/master/std/variant.d#L544#L555
Apr 27 2013
parent reply "David Eagen" <davideagen mailinator.com> writes:
On Saturday, 27 April 2013 at 17:42:54 UTC, Idan Arye wrote:

 The way it works now, is that if the size is too big they use a 
 reference instead: 
 https://github.com/D-Programming-Language/phobos/blob/master/std/variant.d#L544#L555


So is the bug in std.concurrency and they way it uses Variant or 
is the bug in Variant?
Apr 29 2013
next sibling parent "Anonimous" <tr1 google.com> writes:
On Tuesday, 30 April 2013 at 00:04:04 UTC, David Eagen wrote:

 On Saturday, 27 April 2013 at 17:42:54 UTC, Idan Arye wrote:

 The way it works now, is that if the size is too big they use 
 a reference instead: 
 https://github.com/D-Programming-Language/phobos/blob/master/std/variant.d#L544#L555


 So is the bug in std.concurrency and they way it uses Variant 
 or is the bug in Variant?


Ping.
May 09 2013
prev sibling parent reply "David Nadlinger" <see klickverbot.at> writes:
On Tuesday, 30 April 2013 at 00:04:04 UTC, David Eagen wrote:

 On Saturday, 27 April 2013 at 17:42:54 UTC, Idan Arye wrote:

 The way it works now, is that if the size is too big they use 
 a reference instead: 
 https://github.com/D-Programming-Language/phobos/blob/master/std/variant.d#L544#L555


 So is the bug in std.concurrency and they way it uses Variant 
 or is the bug in Variant?


It's a variant bug, please make sure it is on Bugzilla.

David
May 09 2013
parent reply "Anonimous" <tr1 google.com> writes:
On Thursday, 9 May 2013 at 12:36:36 UTC, David Nadlinger wrote:

 On Tuesday, 30 April 2013 at 00:04:04 UTC, David Eagen wrote:

 On Saturday, 27 April 2013 at 17:42:54 UTC, Idan Arye wrote:

 The way it works now, is that if the size is too big they use 
 a reference instead: 
 https://github.com/D-Programming-Language/phobos/blob/master/std/variant.d#L544#L555


 So is the bug in std.concurrency and they way it uses Variant 
 or is the bug in Variant?


 It's a variant bug, please make sure it is on Bugzilla.

 David


Yes, it is reported by Tavi Cacina
http://d.puremagic.com/issues/show_bug.cgi?id=10017

Sorry,I ment that it's an important bug,but maybe everybody was 
busy
with dconf and just didn't do anything with it.

There is already pull,could you tell about its status?
May 09 2013
parent "David Nadlinger" <see klickverbot.at> writes:
On Thursday, 9 May 2013 at 12:42:25 UTC, Anonimous wrote:

 Sorry,I ment that it's an important bug,but maybe everybody was 
 busy
 with dconf and just didn't do anything with it.


Yep, things are only slowly getting back to normality as jet lag 
wears off and the recordings are taken care of… ;)


 There is already pull,could you tell about its status?


See my comment there.

David
May 09 2013