• Shachar Shemesh (41/41) Dec 05 2017 import std.algorithm: move;
• Nemanja Boric (11/55) Dec 05 2017 ```
• =?UTF-8?Q?Ali_=c3=87ehreli?= (8/10) Dec 05 2017 The same issue came up recently in the learn group regarding

Shachar Shemesh <shachar weka.io> writes:

import std.algorithm: move;
import std.stdio;
import std.string;

class A {
     int val;

     override string toString() const {
         return "A(%s)".format(val);
     }
}

struct B {
     int val;
}

void main() {
     B b = B(12);
     B* bp = &b;
     B* bp2;

     writefln("bp=%s bp2=%s", bp, bp2);
     move( bp, bp2 );
     writefln("bp=%s bp2=%s", bp, bp2);

     A a1 = new A();
     a1.val = 42;
     A a2;

     writefln("a1=%s (%s) a2=%s (%s)", a1, cast(void*)a1, a2, 
cast(void*)a2);
     move( a1, a2 );
     writefln("a1=%s (%s) a2=%s (%s)", a1, cast(void*)a1, a2, 
cast(void*)a2);

     B b2;
     writefln("b=%s b2=%s", b, b2);
     move( b, b2 );
     writefln("b=%s b2=%s", b, b2);
}

Answer:
bp=7FFFAB559970 bp2=null
bp=7FFFAB559970 bp2=7FFFAB559970
a1=A(42) (7FD1B79E9000) a2=null (null)
a1=A(42) (7FD1B79E9000) a2=A(42) (7FD1B79E9000)
b=B(12) b2=B(0)
b=B(12) b2=B(12)

"move" was supposed to initialize "source" to init. This does not appear 
to be the case. Is that a bug? Where?

Nemanja Boric <4burgos gmail.com> writes:

On Tuesday, 5 December 2017 at 14:11:02 UTC, Shachar Shemesh 
wrote:
 import std.algorithm: move;
 import std.stdio;
 import std.string;

 class A {
     int val;

     override string toString() const {
         return "A(%s)".format(val);
     }
 }

 struct B {
     int val;
 }

 void main() {
     B b = B(12);
     B* bp = &b;
     B* bp2;

     writefln("bp=%s bp2=%s", bp, bp2);
     move( bp, bp2 );
     writefln("bp=%s bp2=%s", bp, bp2);

     A a1 = new A();
     a1.val = 42;
     A a2;

     writefln("a1=%s (%s) a2=%s (%s)", a1, cast(void*)a1, a2, 
 cast(void*)a2);
     move( a1, a2 );
     writefln("a1=%s (%s) a2=%s (%s)", a1, cast(void*)a1, a2, 
 cast(void*)a2);

     B b2;
     writefln("b=%s b2=%s", b, b2);
     move( b, b2 );
     writefln("b=%s b2=%s", b, b2);
 }

 Answer:
 bp=7FFFAB559970 bp2=null
 bp=7FFFAB559970 bp2=7FFFAB559970
 a1=A(42) (7FD1B79E9000) a2=null (null)
 a1=A(42) (7FD1B79E9000) a2=A(42) (7FD1B79E9000)
 b=B(12) b2=B(0)
 b=B(12) b2=B(12)

 "move" was supposed to initialize "source" to init. This does 
 not appear to be the case. Is that a bug? Where?

```
b=B(12) b2=B(0)
b=B(12) b2=B(12)
```

bit will change if you declare destructor in your struct. As per 
the documentation:

 If T is a struct with a destructor or postblit defined, source 
 is reset to its .init value after it is moved into target, 
 otherwise it is left unchanged.

as for others I understand you have the same problem here - per 
documentation, these are not  structs with destructors, so moving 
the pointers (references) doesn't clear the source one.

=?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:

On 12/05/2017 06:11 AM, Shachar Shemesh wrote:

 "move" was supposed to initialize "source" to init. This does not appear
 to be the case. Is that a bug? Where?

The same issue came up recently in the learn group regarding 
moveFront(). The documentation fails to mention that the .init behavior 
is only for hasElaborateCopyConstructor!(ElementType!R):

   http://forum.dlang.org/post/ovs6hq$1gfh$1 digitalmars.com

Finally opened an issue about that one:

   https://issues.dlang.org/show_bug.cgi?id=18036

Ali