Hello.

I am working through Alexandrescu's "The D Programming Language".  He has an example in his concurrency chapter which I can't compile.  It looks to be missing a few import packages, but getting over that, I still can't get the example to work:

import std.concurrency, std.stdio;
import std.contracts, std.typecons;  /* I added this */

void main() {
  auto low = 0, high = 25;
  auto tid = spawn(&writer);

  foreach( i; low .. high) {
    writeln("Main thread: ", i);
    tid.send(thisTid, i);
    enforce( receiveOnly!Tid() == tid);
  }

  return;
}

void writer() {
  for( ;; ) {
    auto msg = receiveOnly!(Tid, int)();
    writeln( "Secondary thread: ", msg[1]);
    msg[0].send(thisTid);
  }

  return;
}


I get the following compiler error:

$ dmd Thread2.d

Thread2.d(10): Error: template std.typecons.Tuple!(Tid).Tuple.opEquals(T) if
(is(typeof(T.field))) does not match any function template declaration
Thread2.d(10): Error: template std.typecons.Tuple!(Tid).Tuple.opEquals(T) if
(is(typeof(T.field))) cannot deduce template function from argument types !()(Tid)


$ dmd --help
Digital Mars D Compiler v2.042
Copyright (c) 1999-2010 by Digital Mars written by Walter Bright
Documentation: http://www.digitalmars.com/d/2.0/index.html


So, what am I doing wrong here?

thanks.

On 26.07.2010 19:45, dcoder wrote:
> Hello.
>
>    
[snip]
> $ dmd --help
> Digital Mars D Compiler v2.042
> Copyright (c) 1999-2010 by Digital Mars written by Walter Bright
> Documentation: http://www.digitalmars.com/d/2.0/index.html
>
>
>    
I suggest updating compiler - it's should be 2.047 now. The outdated distribution could also feature some bugs in std.concurency.
> So, what am I doing wrong here?
>
> thanks.
>
>    


-- 
Dmitry Olshansky

Dmitry Olshansky wrote:

> On 26.07.2010 19:45, dcoder wrote:
>> Hello.
>>
>> 
> [snip]
>> $ dmd --help
>> Digital Mars D Compiler v2.042
>> Copyright (c) 1999-2010 by Digital Mars written by Walter Bright
>> Documentation: http://www.digitalmars.com/d/2.0/index.html
>>
>>
>> 
> I suggest updating compiler - it's should be 2.047 now. The outdated distribution could also feature some bugs in std.concurency.
>> So, what am I doing wrong here?
>>
>> thanks.
>>
>> 
> 
> 
Doesn't work for 2.047 either.

dthreadpass.d(19): Error: no [] operator overload for type Tuple!(Tid,int)
dthreadpass.d(20): Error: no [] operator overload for type Tuple!(Tid,int)

== Quote from Rory Mcguire (rjmcguire@gm_no_ail.com)'s article
> Dmitry Olshansky wrote:
> > On 26.07.2010 19:45, dcoder wrote:
> >> $ dmd --help
> >> Digital Mars D Compiler v2.042
> >> Copyright (c) 1999-2010 by Digital Mars written by Walter Bright
> >> Documentation: http://www.digitalmars.com/d/2.0/index.html
> >>
> >>
> >>
> > I suggest updating compiler - it's should be 2.047 now. The outdated distribution could also feature some bugs in std.concurency.
> Doesn't work for 2.047 either.
> dthreadpass.d(19): Error: no [] operator overload for type Tuple!(Tid,int)
> dthreadpass.d(20): Error: no [] operator overload for type Tuple!(Tid,int)


Yep, I get that same error after upgrading my compiler.

$ dmd --help
Digital Mars D Compiler v2.047
Copyright (c) 1999-2010 by Digital Mars written by Walter Bright
Documentation: http://www.digitalmars.com/d/2.0/index.html



thanks.

On Mon, Jul 26, 2010 at 19:11, dcoder <dcoder@devnull.dev> wrote:

> == Quote from Rory Mcguire (rjmcguire@gm_no_ail.com)'s article
> > Dmitry Olshansky wrote:
>


std.typecons.Tuple fields cannot be indexed like arrays, Andrei made a mistake. To access field  #n, use ._n or .field[n]. There is no difference between the two.

void writer() {
 for( ;; ) {
   auto msg = receiveOnly!(Tid, int)(); // msg is a Tuple!(Tid, int), msg._0
is a Tid, msg._1 is an int.
   writeln( "Secondary thread: ", msg._1);
   msg._0.send(thisTid);
 }
}

Also, in my case, the return; in writer must be commented out, or DMD complains it cannot be reached.


Philippe

Philippe Sigaud wrote:

> On Mon, Jul 26, 2010 at 19:11, dcoder <dcoder@devnull.dev> wrote:
> 
>> == Quote from Rory Mcguire (rjmcguire@gm_no_ail.com)'s article
>> > Dmitry Olshansky wrote:
>>
> 
> 
> std.typecons.Tuple fields cannot be indexed like arrays, Andrei made a mistake. To access field  #n, use ._n or .field[n]. There is no difference between the two.
> 
> void writer() {
>  for( ;; ) {
>    auto msg = receiveOnly!(Tid, int)(); // msg is a Tuple!(Tid, int),
>    msg._0
> is a Tid, msg._1 is an int.
>    writeln( "Secondary thread: ", msg._1);
>    msg._0.send(thisTid);
>  }
> }
> 
> Also, in my case, the return; in writer must be commented out, or DMD complains it cannot be reached.
> 
> 
> Philippe


Interesting, I didn't have to comment out return; using dmd 2.047 on linux

On Tue, Jul 27, 2010 at 11:25, Rory Mcguire <rjmcguire@gm_no_ail.com> wrote:

>
> > Also, in my case, the return; in writer must be commented out, or DMD complains it cannot be reached.
>


>
> Interesting, I didn't have to comment out return; using dmd 2.047 on linux
>

I think I have -w (warnings treated as errors?) always checked. That's my
Code::Blocks default configuration for DMD.
I was on Windows for this test. I never cheked if there was any difference
between OSes for this :-)

Philippe Sigaud wrote:

> On Tue, Jul 27, 2010 at 11:25, Rory Mcguire <rjmcguire@gm_no_ail.com> wrote:
> 
>>
>> > Also, in my case, the return; in writer must be commented out, or DMD complains it cannot be reached.
>>
> 
> 
>>
>> Interesting, I didn't have to comment out return; using dmd 2.047 on linux
>>
> 
> I think I have -w (warnings treated as errors?) always checked. That's my
> Code::Blocks default configuration for DMD.
> I was on Windows for this test. I never cheked if there was any difference
> between OSes for this :-)

:) thanks Philippe

== Quote from Rory Mcguire (rjmcguire@gm_no_ail.com)'s article
> Philippe Sigaud wrote:
> >> > Also, in my case, the return; in writer must be commented out, or DMD complains it cannot be reached.
> >>
> >
> >
> >>
> >> Interesting, I didn't have to comment out return; using dmd 2.047 on linux
> >>
> >
> > I think I have -w (warnings treated as errors?) always checked. That's my
> > Code::Blocks default configuration for DMD.
> > I was on Windows for this test. I never cheked if there was any difference
> > between OSes for this :-)
> :) thanks Philippe


Actually, after making the changes that you suggest, Philippe my program works. Thanks.

However, I did not have to comment out the return statement.  But when I did compile using the -w flag, I do get the compiler error that you describe.

Anyways, thanks for the coding suggestion.

The next release, 2.048, should bring things in line with TDPL.  I had meant to do this for 2.047, but was too busy with other work to finish in time.