Help me investigate a bug to file it.

[monarch_dodra]

On Monday, 8 July 2013 at 18:55:30 UTC, Artur Skawina wrote:
> On 07/08/13 19:54, monarch_dodra wrote:
>> struct S(R)
>> {
>>     R _input;
>>     void foo()
>>     {
>>         static assert(is(typeof(_input[size_t.max .. 
>> size_t.max]))); //ok
>>         static assert(is(typeof(_input[size_t.max .. $]))); 
>> //ok
>>     }
>>     static assert(is(typeof(_input[size_t.max .. 
>> size_t.max]))); //ok
>>     static assert(is(typeof(_input[size_t.max .. $]))); //NOPE!
>> }
>
>> As you can see, the static if behaves differently in a 
>> function, or in the raw body of the struct. Is this normal? 
>> Anybody know what is going on exactly? I'm trying to get more 
>> context here...
>> 
>> -----------------------------------------------
>> 
>> Second, one of the things I found strange was that only *1* of 
>> the two assertions failed. basically, _input[0 .. 1] is fair 
>> game, yet, _input[0 .. $] is not? What gives? I put my nose in 
>> cycles's opDollar. It is written like this:
>
> Did you really mean size_t.*max* above?

Yeah. It's not a runtime test. In this case, I *also* need to 
make sure that the slie operation accepts a size_t arg. If I use 
size_t.min, it statically evaluates to zero, so the test becomes 
sens-less: saying "fun(size_t.min)" works doesn't actually 
guarantee you can pass a size_t: it may actually only accepts 
ubytes or short indexing.

But I guess that is a detail in the scope of the original problem.

> Anyway, when '$' is rewritten as 'opDollar' and that is defined
> as a non-static method, it would be surprising if calling the
> method did work w/o any context pointer...

But, the "context pointer" *should* be defined as whatever the 
owner of the indexing/slicing object is, no? In this case, it's 
simply _input. It has nothing to do with the "this" pointer being 
available...

If anything, it kind of worries me about *what* the 
implementation is doing with the this pointer, but I haven't been 
able to "trick" it into calling a wrong function.

> Does declaring the opDollar "function" as `static` fix it?
>
> artur

Yes. It does fix it. I think you put your finger exactly on where 
the issue is. I'll report it in the morning. Thank you for 
participating :)