www.digitalmars.com         C & C++   DMDScript  

digitalmars.D - It is a bug ?

reply Du Liang <duliang.21 163.com> writes:
import std.stdio;
class AB{
	int A;
	int B = 2;
	int[] arrA;
	int[] arrB = [2,2,2]; // arrB is static in[]  or bug ?
	this(){
		this.A = 1;
		this.arrA=[1,1,1];
	}
}
void main(){
	AB ab1 = new AB();
	AB ab2 = new AB();
	writeln(ab1.A, " | " ,ab1.B, " | " ,ab1.arrA, " | " ,ab1.arrB);
	writeln(ab2.A, " | " ,ab2.B, " | " ,ab2.arrA, " | " ,ab2.arrB);
	writeln("change...");
	ab1.A = 10; 
	ab1.B = 20; 
	ab1.arrA[0] = 10; 
	ab1.arrB[0] = 20; // ab2.arrB = 20  why? bug?
	writeln(ab1.A, " | " ,ab1.B, " | " ,ab1.arrA, " | " ,ab1.arrB);
	writeln(ab2.A, " | " ,ab2.B, " | " ,ab2.arrA, " | " ,ab2.arrB);
	readln();
}
May 06 2009
next sibling parent reply Jarrett Billingsley <jarrett.billingsley gmail.com> writes:
On Wed, May 6, 2009 at 10:06 AM, Du Liang <duliang.21 163.com> wrote:


 =A0 =A0 =A0 =A0int[] arrB =3D [2,2,2]; // arrB is static in[] =A0or bug ?



Declaring the variable like this uses a single array for all instances
of AB.  You should initialize it in this() instead, or put "arrB =3D
arrB.dup;" in this().
May 06 2009
next sibling parent Georg Wrede <georg.wrede iki.fi> writes:
Denis Koroskin wrote:

 On Wed, 06 May 2009 19:33:03 +0400, Jarrett Billingsley
<jarrett.billingsley gmail.com> wrote:
 

 On Wed, May 6, 2009 at 10:06 AM, Du Liang <duliang.21 163.com> wrote:


        int[] arrB = [2,2,2]; // arrB is static in[]  or bug ?



 of AB.  You should initialize it in this() instead, or put "arrB =
 arrB.dup;" in this().



 I believe this is a horrible inconsistency. It shouldn't be allowed in first
place, because typeof([2,2,2]) is immutable(int)[] in this context.



Issue 2947 Submitted
May 06 2009
prev sibling next sibling parent Georg Wrede <georg.wrede iki.fi> writes:
Denis Koroskin wrote:

 On Wed, 06 May 2009 19:33:03 +0400, Jarrett Billingsley wrote:

 On Wed, May 6, 2009 at 10:06 AM, Du Liang wrote:


        int[] arrB = [2,2,2]; // arrB is static in[]  or bug ?



 of AB.  You should initialize it in this() instead, or put "arrB =
 arrB.dup;" in this().



 in first place, because typeof([2,2,2]) is immutable(int)[] in this
 context.



writeln(typeof([2,2,2]).stringof);

int[3u]


A literal string seems not to be immutable.
May 06 2009
prev sibling parent reply grauzone <none example.net> writes:
Denis Koroskin wrote:

 On Wed, 06 May 2009 19:33:03 +0400, Jarrett Billingsley
<jarrett.billingsley gmail.com> wrote:
 

 On Wed, May 6, 2009 at 10:06 AM, Du Liang <duliang.21 163.com> wrote:


        int[] arrB = [2,2,2]; // arrB is static in[]  or bug ?



 of AB.  You should initialize it in this() instead, or put "arrB =
 arrB.dup;" in this().



 I believe this is a horrible inconsistency. It shouldn't be allowed in first
place, because typeof([2,2,2]) is immutable(int)[] in this context.



DWIM would be to let the compiler automatically move these instructions 
into all ctors.

class A {
    int[] arrB = [2,2,2];
    X x = new X();
    this() {
        code1();
    }
    this(int) {
        code2();
    }
}

would be transformed into

class A {
    int[] arrB;
    X x;
    this() {
        arrB = [2,2,2];
        x = new X();
        code1();
    }
    this(int) {
        arrB = [2,2,2];
        x = new X();
        code2();
    }
}
May 06 2009
parent reply Du Liang <duliang.21 163.com> writes:
grauzone Wrote:


 Denis Koroskin wrote:

 On Wed, 06 May 2009 19:33:03 +0400, Jarrett Billingsley
<jarrett.billingsley gmail.com> wrote:
 

 On Wed, May 6, 2009 at 10:06 AM, Du Liang <duliang.21 163.com> wrote:


        int[] arrB = [2,2,2]; // arrB is static in[]  or bug ?



 of AB.  You should initialize it in this() instead, or put "arrB =
 arrB.dup;" in this().



 I believe this is a horrible inconsistency. It shouldn't be allowed in first
place, because typeof([2,2,2]) is immutable(int)[] in this context.



 DWIM would be to let the compiler automatically move these instructions 
 into all ctors.
 
 class A {
     int[] arrB = [2,2,2];
     X x = new X();
     this() {
         code1();
     }
     this(int) {
         code2();
     }
 }
 
 would be transformed into
 
 class A {
     int[] arrB;
     X x;
     this() {
         arrB = [2,2,2];
         x = new X();
         code1();
     }
     this(int) {
         arrB = [2,2,2];
         x = new X();
         code2();
     }
 }



Thanks!
May 06 2009
parent grauzone <none example.net> writes:
Du Liang wrote:

 grauzone Wrote:
 

 Denis Koroskin wrote:

 On Wed, 06 May 2009 19:33:03 +0400, Jarrett Billingsley
<jarrett.billingsley gmail.com> wrote:


 On Wed, May 6, 2009 at 10:06 AM, Du Liang <duliang.21 163.com> wrote:


        int[] arrB = [2,2,2]; // arrB is static in[]  or bug ?



 of AB.  You should initialize it in this() instead, or put "arrB =
 arrB.dup;" in this().






 into all ctors.

 class A {
     int[] arrB = [2,2,2];
     X x = new X();
     this() {
         code1();
     }
     this(int) {
         code2();
     }
 }

 would be transformed into

 class A {
     int[] arrB;
     X x;
     this() {
         arrB = [2,2,2];
         x = new X();
         code1();
     }
     this(int) {
         arrB = [2,2,2];
         x = new X();
         code2();
     }
 }



 Thanks!



Um... Maybe I should clarify: it does NOT work like that right now! My 
post was more like a feature request.
May 07 2009
prev sibling parent "Denis Koroskin" <2korden gmail.com> writes:
On Wed, 06 May 2009 19:33:03 +0400, Jarrett Billingsley
<jarrett.billingsley gmail.com> wrote:


 On Wed, May 6, 2009 at 10:06 AM, Du Liang <duliang.21 163.com> wrote:


        int[] arrB = [2,2,2]; // arrB is static in[]  or bug ?



 Declaring the variable like this uses a single array for all instances
 of AB.  You should initialize it in this() instead, or put "arrB =
 arrB.dup;" in this().



I believe this is a horrible inconsistency. It shouldn't be allowed in first
place, because typeof([2,2,2]) is immutable(int)[] in this context.
May 06 2009