Compiler error on struct with invariant and postblitz

[Alex Khmara]

On Sat, 01 Jan 2011 20:56:20 -0000, Jonathan M Davis <jmdavisProg at gmx.com>  
wrote:

> On Saturday 01 January 2011 11:17:36 Alex Khmara wrote:
>> Please help: is it compiler bug or I'm doing something wrong?
>>
>> This code:
>>
>> module properties;
>>
>> struct PropertyList {
>> <-->invariant() {
>> <--><-->assert(1);
>> <-->}
>>
>> <-->this(this) {
>> <--><-->_props = [];
>> <-->}
>>
>> <-->string[] _props;
>> }
>>
>>
>> gives compiler error:
>>
>> Error: __result = this is not mutable
>> Error: __result = this is not an lvalue
>>
>> Without invariant all works good.
>
> It's hard to read what you're doing when have those extra arrows in  
> there.
>
> In any case, create a bug report for it. There are several bugs at  
> present with
> invariants not working because of things like a public member function  
> being
> pure (that one you can fix by marking the invariant as pure) or  
> returning a ref.
> My guess would be that the problem relates to bug
> http://d.puremagic.com/issues/show_bug.cgi?id=4867 which makes it so that
> postblit constructors cannot currently copy const or immutable objects,  
> but I
> don't know, since problems with __result have to do with the return  
> value of a
> function (which would be the result of postblit rather than what's  
> passed in).
> So, just create a bug report on it and it can be sorted out with the  
> other
> invariant, postblit, and const problems. For the moment, it probably  
> means that
> you can't have both an invariant and a postblit constructor, which  
> sucks, but
> until the bug is fixed, I don't see what else you can do.
>
> - Jonathan M Davis

Thank you. Sorry for arrows - Midnight Commander marks tabs with them, and  
I forgot to
disable this.

Filed bug: http://d.puremagic.com/issues/show_bug.cgi?id=5397