Hi!

I'm trying to make threads communicate by sending an immutable address book to each thread.


Code:

Tid[string] addressBook;

addressBook["Some"] = sdfsdf;
addressBook["Input"] = sdfsdf;

auto sharedAddressBook = cast(immutable(Tid[string]))(addressBook);
send(tid, sharedAddressBook); // <- error


Output log:

C:\D\dmd2\windows\bin\..\..\src\phobos\std\variant.d(439): Error: cannot modify immutable expression (*zis)[args[1].get()]
C:\D\dmd2\windows\bin\..\..\src\phobos\std\variant.d(632): Error: template instance std.variant.VariantN!20LU.VariantN.handler!(immutable(int[immutable(string)])) error instantiating
C:\D\dmd2\windows\bin\..\..\src\phobos\std\variant.d(548):        instantiated from here: opAssign!(immutable(int[immutable(string)]))
C:\D\dmd2\windows\bin\..\..\src\phobos\std\concurrency.d(117):        instantiated from here: __ctor!(immutable(int[immutable(string)]))
C:\D\dmd2\windows\bin\..\..\src\phobos\std\concurrency.d(639):        instantiated from here: __ctor!(immutable(int[immutable(string)]))
C:\D\dmd2\windows\bin\..\..\src\phobos\std\concurrency.d(629):        ... (1 instantiations, -v to show) ...
C:\D\dmd2\windows\bin\..\..\src\phobos\std\concurrency.d(605):        instantiated from here: _send!(immutable(int[immutable(string)]))
src\aelia\aelia.d(42):        instantiated from here: send!(immutable(int[immutable(string)]))
Building build\x64\Debug\AeliaD.exe failed!


variant.d:
...
else static if (isAssociativeArray!(A))
{
    (*zis)[args[1].get!(typeof(A.init.keys[0]))] // <- line 439
        = args[0].get!(typeof(A.init.values[0]));
    break;
}
...


What am I doing wrong? Is there a proper way to pass an associative array to another thread?

I also found a thread on the forum http://forum.dlang.org/post/mailman.209.1348312788.5162.digitalmars-d-learn@puremagic.com
that saying it is a bug in Variant, but that bug was fixed already. Have I found a new one? %)


Sincerely,
Alexey

Bug 6585 is not fixed. Variant wasn't written for shared and immutable types. As a workaround wrap the array in a class.

On Friday, 5 August 2016 at 13:14:41 UTC, Kagamin wrote:
> Bug 6585 is not fixed. Variant wasn't written for shared and immutable types. As a workaround wrap the array in a class.

Thanks! It worked.

Though it's strange that
>Variant wasn't written for shared and immutable types
because, for instance, in TDPL it has been used in multithreading context.