[PATCH] Use the correct from type in a SCS

[Richard Smith]

The problem in PR20218 is visible in its notes:

test.cpp(4,3) :  note: candidate constructor [with X = int, Y = void ()]
  pair(X&&, Y&&);
  ^

This deduction is wrong. We should get Y = void (&)(). Presumably the
'deduce an lvalue reference if an rvalue reference to T binds to an lvalue'
rule isn't being applied appropriately in the case where the lvalue is an
overload set.


On Tue, Jul 8, 2014 at 3:13 PM, Ehsan Akhgari <ehsan.akhgari at gmail.com>
wrote:

> On Tue, Jul 8, 2014 at 6:05 PM, Richard Smith <richard at metafoo.co.uk>
> wrote:
>
>> On Sun, Jul 6, 2014 at 12:16 PM, Ehsan Akhgari <ehsan.akhgari at gmail.com>
>> wrote:
>>
>>> Hi doug.gregor,
>>>
>>> If during constructing a standard conversion sequence, we resolve an
>>> overload, we need to adjust the from type in the SCS according to the
>>> resolved operator.
>>>
>>> I found this bug when debugging PR20218.  It doesn't completely fix that
>>> test case though.
>>>
>>
>> The fix looks correct, but please provide some kind of test case for this
>> patch (even if it doesn't solve PR20218's test case).
>>
>
> I tried to do that, but I wasn't able to write a simpler test case similar
> to that of PR20218 which would have an observable outcome different after
> this patch...  Any ideas how I can write a good test case for this?
>
> Thanks!
> --
> Ehsan
> <http://ehsanakhgari.org/>
>
>
>>
>>
>>> http://reviews.llvm.org/D4402
>>>
>>> Files:
>>>   lib/Sema/SemaOverload.cpp
>>>
>>> Index: lib/Sema/SemaOverload.cpp
>>> ===================================================================
>>> --- lib/Sema/SemaOverload.cpp
>>> +++ lib/Sema/SemaOverload.cpp
>>> @@ -1462,6 +1462,7 @@
>>>        // We were able to resolve the address of the overloaded function,
>>>        // so we can convert to the type of that function.
>>>        FromType = Fn->getType();
>>> +      SCS.setFromType(FromType);
>>>
>>>        // we can sometimes resolve &foo<int> regardless of ToType, so
>>> check
>>>        // if the type matches (identity) or we are converting to bool
>>>
>>> _______________________________________________
>>> cfe-commits mailing list
>>> cfe-commits at cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
>>>
>>>
>>
>
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