std.concurrency.send problems with immutable

[Marek Janukowicz via Digitalmars-d-learn]

This program works fine:

import std.concurrency;

struct A {
  string a,b;
}

void main () {
  immutable A a = immutable A( "blah" ); 
  send( thisTid, a );
}

But if change struct A declaration to:

struct A {
  string a,b,c;
}

I get this error during compilation:
/opt/dmd2/linux/bin64/../../src/phobos/std/variant.d(653): Error: cannot 
modify immutable expression *p
/opt/dmd2/linux/bin64/../../src/phobos/std/variant.d(580): Error: template 
instance std.variant.VariantN!32LU.VariantN.opAssign!(immutable(A)) error 
instantiating
/opt/dmd2/linux/bin64/../../src/phobos/std/concurrency.d(117):        
instantiated from here: __ctor!(immutable(A))
/opt/dmd2/linux/bin64/../../src/phobos/std/concurrency.d(628):        
instantiated from here: __ctor!(immutable(A))
/opt/dmd2/linux/bin64/../../src/phobos/std/concurrency.d(618):        
instantiated from here: _send!(immutable(A))
/opt/dmd2/linux/bin64/../../src/phobos/std/concurrency.d(594):        
instantiated from here: _send!(immutable(A))

Is this is a bug?



On a related note - sometimes when sending a shared struct I get a 
compilation error similar to this:

/opt/dmd2/linux/bin64/../../src/phobos/std/variant.d(638): Error: function 
core.stdc.string.memcpy (void* s1, const(void*) s2, ulong n) is not callable 
using argument types (ubyte[32]*, shared(Notification)*, ulong)
/opt/dmd2/linux/bin64/../../src/phobos/std/variant.d(580): Error: template 
instance std.variant.VariantN!32LU.VariantN.opAssign!(shared(Notification)) 
error instantiating
/opt/dmd2/linux/bin64/../../src/phobos/std/concurrency.d(117):        
instantiated from here: __ctor!(shared(Notification))
/opt/dmd2/linux/bin64/../../src/phobos/std/concurrency.d(628):        
instantiated from here: __ctor!(shared(Notification))
/opt/dmd2/linux/bin64/../../src/phobos/std/concurrency.d(618):        
instantiated from here: _send!(shared(Notification))
/opt/dmd2/linux/bin64/../../src/phobos/std/concurrency.d(594):        
instantiated from here: _send!(shared(Notification))

If I then add more fields to the struct (eg. dummy "string a,b") it compiles 
fine.

Is this another bug or am I missing something?


-- 
Marek Janukowicz