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digitalmars.D.announce - DIP1004: Inherited Constructors

reply Dicebot <public dicebot.lv> writes:
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From: Dicebot <public dicebot.lv>
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Subject: DIP1004: Inherited Constructors

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DIP 1004 is merged to the queue and open for public informal feedback.

PR: https://github.com/dlang/DIPs/pull/42

Initial merged document:
https://github.com/dlang/DIPs/blob/master/DIPs/DIP1004.md

If you want the change to be approved and have ideas how to improve it
to better match on
https://github.com/dlang/DIPs/blob/master/GUIDELINES.md and existing
published reviews - please submit new PR with editorial and ping
original author.


--j0vB8RSNEFOSvTc099tSEoLnkhphwtBJ3--
Nov 27 2016
next sibling parent reply rikki cattermole <rikki cattermole.co.nz> writes:
On 28/11/2016 3:38 PM, Dicebot wrote:

 DIP 1004 is merged to the queue and open for public informal feedback.

 PR: https://github.com/dlang/DIPs/pull/42

 Initial merged document:
 https://github.com/dlang/DIPs/blob/master/DIPs/DIP1004.md

 If you want the change to be approved and have ideas how to improve it
 to better match on
 https://github.com/dlang/DIPs/blob/master/GUIDELINES.md and existing
 published reviews - please submit new PR with editorial and ping
 original author.


A few errors like this are in it:

class ParseException : Exception { }
{
Nov 27 2016
parent Dicebot <public dicebot.lv> writes:
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From: Dicebot <public dicebot.lv>
Newsgroups: d,i,g,i,t,a,l,m,a,r,s,.,D,.,a,n,n,o,u,n,c,e
Subject: Re: DIP1004: Inherited Constructors
References: <o1g5a9$2r3l$1 digitalmars.com> <o1g6fc$2t0o$1 digitalmars.com>
In-Reply-To: <o1g6fc$2t0o$1 digitalmars.com>

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On 11/28/2016 04:57 AM, rikki cattermole wrote:

 On 28/11/2016 3:38 PM, Dicebot wrote:

 DIP 1004 is merged to the queue and open for public informal feedback.=





 PR: https://github.com/dlang/DIPs/pull/42

 Initial merged document:
 https://github.com/dlang/DIPs/blob/master/DIPs/DIP1004.md

 If you want the change to be approved and have ideas how to improve it=





 to better match on
 https://github.com/dlang/DIPs/blob/master/GUIDELINES.md and existing
 published reviews - please submit new PR with editorial and ping
 original author.


=20
 A few errors like this are in it:
=20
 class ParseException : Exception { }
 {


Would you mind a PR? :) I am afraid my eyes are too sloppy after
re-reading the text too many times.



--JFPE4HwCdV43sq6LRRXcbSJbfmq31I2wQ--
Nov 29 2016
prev sibling parent reply Arafel <er.krali gmail.com> writes:
On Monday, 28 November 2016 at 02:38:00 UTC, Dicebot wrote:

 DIP 1004 is merged to the queue and open for public informal 
 feedback.

 PR: https://github.com/dlang/DIPs/pull/42

 Initial merged document: 
 https://github.com/dlang/DIPs/blob/master/DIPs/DIP1004.md

 If you want the change to be approved and have ideas how to 
 improve it to better match on 
 https://github.com/dlang/DIPs/blob/master/GUIDELINES.md and 
 existing published reviews - please submit new PR with 
 editorial and ping original author.


I think I might be a bit late to the party, and I'm still quite 
new in D... but wouldn't a variadic template constructor work? 
The usual rules of templates would still let you override a 
constructor if needed.

---
class A {
	this() { }
	this(int a) { }
}
class B : A {
	// Here we inherit all of A's constructors.
	this(Args...)(Args args) {
		super(args);
	}
	this(string s) { }
}
void main() {
	B b1 = new B(42);
	B b2 = new B("foo");
}
---

I've been playing with it, and the only problems I can see are 
with specialization and casting (i.e. B defines this(float), but 
you want to call A's this(int), the int will be promoted to float 
and B's version will be used). A way of disabling them would be 
needed, though... perhaps assert(0)?
Nov 29 2016
parent Dicebot <public dicebot.lv> writes:
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From: Dicebot <public dicebot.lv>
Newsgroups: d,i,g,i,t,a,l,m,a,r,s,.,D,.,a,n,n,o,u,n,c,e
Subject: Re: DIP1004: Inherited Constructors
References: <o1g5a9$2r3l$1 digitalmars.com>
 <zhemjhreqduwopsoakuw forum.dlang.org>
In-Reply-To: <zhemjhreqduwopsoakuw forum.dlang.org>

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On 11/29/2016 12:04 PM, Arafel wrote:

 I think I might be a bit late to the party, and I'm still quite new in
 D... but wouldn't a variadic template constructor work? The usual rules=



 of templates would still let you override a constructor if needed.
=20
 ---
 class A {
     this() { }
     this(int a) { }
 }
 class B : A {
     // Here we inherit all of A's constructors.
     this(Args...)(Args args) {
         super(args);
     }
     this(string s) { }
 }
 void main() {
     B b1 =3D new B(42);
     B b2 =3D new B("foo");
 }
 ---
=20
 I've been playing with it, and the only problems I can see are with
 specialization and casting (i.e. B defines this(float), but you want to=



 call A's this(int), the int will be promoted to float and B's version
 will be used). A way of disabling them would be needed, though...
 perhaps assert(0)?


Have just answered a similar question in a PR thread:
https://github.com/dlang/DIPs/pull/42#issuecomment-263562276


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Nov 29 2016