[Issue 926] New: Implicit conversion from Derived[] to Base[]

[Issue 926] Revival of implicit conversion from Derived[] to Base[] not noted in changelog

Feb 24, 2009

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Jan 08, 2011

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Jan 29, 2012

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http://d.puremagic.com/issues/show_bug.cgi?id=926 Summary: Implicit conversion from Derived[] to Base[] Product: D Version: unspecified Platform: All OS/Version: All Status: NEW Severity: normal Priority: P2 Component: DMD AssignedTo: bugzilla@digitalmars.com ReportedBy: csantander619@gmail.com In http://www.digitalmars.com/webnews/newsgroups.php?art_group=digitalmars.D&article_id=47590, Kan noted that this was again allowed: class A {} class B : A {} void main() { B [] b; A [] a = b; } I don't know if the docs mention it, but it seems to have been re-allowed out of the blue. --

http://d.puremagic.com/issues/show_bug.cgi?id=926 thomas-dloop@kuehne.cn changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |INVALID ------- Comment #1 from thomas-dloop@kuehne.cn 2007-04-05 11:33 ------- http://www.digitalmars.com/d/arrays.html > > A dynamic array T[] can be implicitly converted to one of the following: > > * U[] > * void[] > > Where U is a base class of T. > --

http://d.puremagic.com/issues/show_bug.cgi?id=926 smjg@iname.com changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |smjg@iname.com Status|RESOLVED |REOPENED Component|DMD |www.digitalmars.com Resolution|INVALID | Summary|Implicit conversion from |Revival of implicit |Derived[] to Base[] |conversion from Derived[] to | |Base[] not noted in | |changelog ------- Comment #2 from smjg@iname.com 2009-02-24 09:30 ------- So the bug is that either: (a) It was disallowed in 0.73 according to the changelog, but the spec itself not updated. The 'bug' that it didn't behave according to spec was subsequently fixed, but Walter completely forgot about the time when the anomaly was introduced. (b) It was disallowed in 0.73, the spec updated, and then the reversion both in the spec and in the compiler was inadvertently left out of the changelog. --

http://d.puremagic.com/issues/show_bug.cgi?id=926 Stewart Gordon <smjg@iname.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Priority|P5 |P2 Version|D2 |unspecified Severity|critical |normal --- Comment #3 from Stewart Gordon <smjg@iname.com> 2011-01-08 15:26:39 PST --- The version, priority and severity changes just made make no sense at all. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------

http://d.puremagic.com/issues/show_bug.cgi?id=926 Walter Bright <bugzilla@digitalmars.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Version|unspecified |D1 Severity|normal |enhancement --- Comment #4 from Walter Bright <bugzilla@digitalmars.com> 2012-01-29 02:10:38 PST --- This is D1 only. D2 does not allow it. The D1 spec allows it, and changing it would be an enhancement. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------

http://d.puremagic.com/issues/show_bug.cgi?id=926 Stewart Gordon <smjg@iname.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords|accepts-invalid | Severity|enhancement |normal --- Comment #5 from Stewart Gordon <smjg@iname.com> 2012-01-29 07:15:47 PST --- The D1 spec allows what? The spec and the changelog to contradict each other? In which DMD version was this misfeature revived, anyway? -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------

January 29, 2012

[Issue 926] Revival of implicit conversion from Derived[] to Base[] not noted in changelog

Posted by Walter Bright
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Walter Bright

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http://d.puremagic.com/issues/show_bug.cgi?id=926


Walter Bright <bugzilla@digitalmars.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |RESOLVED
         Resolution|                            |WONTFIX


--- Comment #6 from Walter Bright <bugzilla@digitalmars.com> 2012-01-29 10:29:25 PST ---
(In reply to comment #5)
> The D1 spec allows what?

It allows implict conversion of an array of derived classes to an array of base classes. Thomas quoted the relevant verbage.


> The spec and the changelog to contradict each other?

What matters is what the spec says and what the compiler does now. If someone wants to go through the compiler/spec diffs from years ago to see when things changed, that's fine and I'll fold in changelog changes if they present them, but I've got a lot of current issues to address, and historical spelunking is off the radar.


> In which DMD version was this misfeature revived, anyway?

I don't know. I agree it is a misfeature, but I am loathe to break existing D1 code at this point, so I believe it should stay as it is.

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http://d.puremagic.com/issues/show_bug.cgi?id=926 Stewart Gordon <smjg@iname.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|RESOLVED |REOPENED Resolution|WONTFIX | AssignedTo|bugzilla@digitalmars.com |smjg@iname.com --- Comment #7 from Stewart Gordon <smjg@iname.com> 2012-01-30 08:55:26 PST --- (In reply to comment #6) > What matters is what the spec says and what the compiler does now. If someone wants to go through the compiler/spec diffs from years ago to see when things changed, that's fine and I'll fold in changelog changes if they present them, The standard meaning of WONTFIX is "this issue is to stay as it is" not "I personally can't be bothered/don't have time to deal with it". The way to indicate the latter is to leave it open and reassign it to nobody - this shows that it's free for anybody to take the issue and work on it. Here's an idea: I'll have a look at it myself over the next few days. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------

http://d.puremagic.com/issues/show_bug.cgi?id=926 Walter Bright <bugzilla@digitalmars.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |bugzilla@digitalmars.com --- Comment #8 from Walter Bright <bugzilla@digitalmars.com> 2012-01-30 11:27:08 PST --- (In reply to comment #7) > Here's an idea: I'll have a look at it myself over the next few days. I'll be happy to merge in any changes you suggest. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------

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