• James Blachly (6/6) May 02 2019 I work a lot with C functions, many of which yield pointer + length.
• ag0aep6g (5/10) May 02 2019 Just slice the pointer with the length:
• James Blachly (4/9) May 02 2019 Perfect thanks. I searched but without using the magic word "slice" I
• =?UTF-8?Q?Ali_=c3=87ehreli?= (5/16) May 03 2019 Looks like I indexed it under "slice from pointer":
• James Blachly (2/22) May 04 2019 Thanks Ali, also helpful examples!

James Blachly <james.blachly gmail.com> writes:

I work a lot with C functions, many of which yield pointer + length.

Is there a way to cast this or materialize a D-style array backed by the 
already allocated data (with length) to avoid copies which slow things down?

I recognize memory management is a complication. Typically, I would be 
responsible for free'ing the array later.

Thanks in advance

ag0aep6g <anonymous example.com> writes:

On 02.05.19 22:03, James Blachly wrote:
 I work a lot with C functions, many of which yield pointer + length.
 
 Is there a way to cast this or materialize a D-style array backed by the 
 already allocated data (with length) to avoid copies which slow things 
 down?

Just slice the pointer with the length:

     int* ptr;
     size_t len;
     int[] arr = ptr[0 .. len];

James Blachly <james.blachly gmail.com> writes:

On 5/2/19 4:05 PM, ag0aep6g wrote:
 Just slice the pointer with the length:
 
      int* ptr;
      size_t len;
      int[] arr = ptr[0 .. len];

Perfect thanks. I searched but without using the magic word "slice" I 
couldn't find meaningful results.

Thanks again.

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

On 05/02/2019 08:21 PM, James Blachly wrote:
 On 5/2/19 4:05 PM, ag0aep6g wrote:
 Just slice the pointer with the length:

 =C2=A0=C2=A0=C2=A0=C2=A0 int* ptr;
 =C2=A0=C2=A0=C2=A0=C2=A0 size_t len;
 =C2=A0=C2=A0=C2=A0=C2=A0 int[] arr =3D ptr[0 .. len];

=20
 Perfect thanks. I searched but without using the magic word "slice" I=20
 couldn't find meaningful results.
=20
 Thanks again.

Looks like I indexed it under "slice from pointer":


http://ddili.org/ders/d.en/pointers.html#ix_pointers.slice%20from%20point=
er

Ali

James Blachly <james.blachly gmail.com> writes:

On 5/3/19 5:42 AM, Ali Çehreli wrote:
 On 05/02/2019 08:21 PM, James Blachly wrote:
 On 5/2/19 4:05 PM, ag0aep6g wrote:
 Just slice the pointer with the length:

      int* ptr;
      size_t len;
      int[] arr = ptr[0 .. len];

 Perfect thanks. I searched but without using the magic word "slice" I 
 couldn't find meaningful results.

 Thanks again.

 
 Looks like I indexed it under "slice from pointer":
 
 
 http://ddili.org/ders/d.en/pointers.html#ix_pointers.slice%20from%20pointer
 
 Ali
 

Thanks Ali, also helpful examples!