r263732 - Remove defaulted move ops, the type is zero-cost copyable anyway, so there's no need for specific move ops

[don hinton via cfe-commits]

I just did some tests, and when a derived class is explicitly moved, e.g.,
with std::move(), the current behavior is (clang++/g++/vc++):

1) if base has implicit move, it gets called
2) if base doesn't have an implicit move (because a copy ctor was define,
etc) copy ctor is called
3) if base class move was explicitly deleted, compile time error

I was surprised by #2.

On Thu, Mar 17, 2016 at 4:51 PM, David Blaikie <dblaikie at gmail.com> wrote:

>
>
> On Thu, Mar 17, 2016 at 1:41 PM, don hinton <hintonda at gmail.com> wrote:
>
>> Dave:
>>
>> Won't this prevent UnresolvedSet from being movable?
>>
>> I was under the impression that all subobjects (base class in this case)
>> had to be movable in order for the compiler to generate implicit move ops.
>> Is that not the case?
>>
>
> Yeah, I think you're right (I thought the language had been fixed/changed
> here, so that a type with a copyable-but-not-movable member, and a movable
> (but possibly non-copyable member) could still be moved, and just move the
> moveable parts and copy the non-movable parts - but I can't see any
> evidence of that). Added explicit (empty) move ops in r263747
>
>
>>
>> thanks...
>> don
>>
>> On Thu, Mar 17, 2016 at 2:28 PM, David Blaikie via cfe-commits <
>> cfe-commits at lists.llvm.org> wrote:
>>
>>> Author: dblaikie
>>> Date: Thu Mar 17 13:28:16 2016
>>> New Revision: 263732
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=263732&view=rev
>>> Log:
>>> Remove defaulted move ops, the type is zero-cost copyable anyway, so
>>> there's no need for specific move ops
>>>
>>> (addresses MSVC build error, since MSVC 2013 can't generate default move
>>> ops)
>>>
>>> Modified:
>>>     cfe/trunk/include/clang/AST/UnresolvedSet.h
>>>
>>> Modified: cfe/trunk/include/clang/AST/UnresolvedSet.h
>>> URL:
>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/UnresolvedSet.h?rev=263732&r1=263731&r2=263732&view=diff
>>>
>>> ==============================================================================
>>> --- cfe/trunk/include/clang/AST/UnresolvedSet.h (original)
>>> +++ cfe/trunk/include/clang/AST/UnresolvedSet.h Thu Mar 17 13:28:16 2016
>>> @@ -61,9 +61,7 @@ private:
>>>    template <unsigned N> friend class UnresolvedSet;
>>>    UnresolvedSetImpl() = default;
>>>    UnresolvedSetImpl(const UnresolvedSetImpl &) = default;
>>> -  UnresolvedSetImpl(UnresolvedSetImpl &&) = default;
>>>    UnresolvedSetImpl &operator=(const UnresolvedSetImpl &) = default;
>>> -  UnresolvedSetImpl &operator=(UnresolvedSetImpl &&) = default;
>>>
>>>  public:
>>>    // We don't currently support assignment through this iterator, so we
>>> might
>>>
>>>
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>>>
>>
>>
>
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