[dmd-beta] dmd 1.062 and 2.047 beta

[Rainer Schuetze]

Hi,

I've tried to untangle the startsWith code, and here's the minimal test 
case I could come up with so far:

///////////////////////
template binaryFunImpl(bool b)
{
        template Body()
        {
            static assert(b);
            alias bool BodyType;
        }
        alias Body!().BodyType  ReturnType;  // line 9
}

uint startsWith(A)(A a) if (is(binaryFunImpl!(true ).ReturnType)) { 
return 1; }
uint startsWith(A)(A a) if (is(binaryFunImpl!(false).ReturnType)) { 
return 0; }  // line 13

const uint var = startsWith(1);
///////////////////////
dmd produces:

test.d(6): Error: static assert  (b) is false
test.d(9):        instantiated from here: Body!()
test.d(13):        instantiated from here: binaryFunImpl!(false)

The error does not show up if var is not const. Also, dmd 2.032 to 2.045 
do not produce this error (2.046 fails), so it must be some compiler 
regression.

As it seems, the compile time evaluation of startsWith uses the wrong 
specialization. Maybe, it is just not gagging error output?

Any other ideas? I have not yet dived too deep into the template code of 
the compiler, but if nobody has a better clue (and time), I can give it 
a try.

Rainer

Andrei Alexandrescu wrote:
> Thanks. It may take a while before I can tend to this. Could someone 
> else look at it?
>
> Andrei
>
> On 06/10/2010 12:53 PM, Rainer Schuetze wrote:
>> Sorry, but it still doesn't work. The error occurs when the expression
>> is evaluated at compile time, so the code added to the unittest does not
>> cover the issue.
>>
>> Rainer
>>
>> Andrei Alexandrescu wrote:
>>> Apologies. svn up should fix it, and bring some more goodies too :o).
>>>
>>> Andrei
>>>
>>> On 06/10/2010 10:14 AM, Don Clugston wrote:
>>>> const bool fails = startsWith("ab", "a");
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>>>
>>
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