Strange warning in C++11 range based for loop

[Andrew Haley]

On 08/30/2011 06:14 PM, Ian Lance Taylor wrote:
> Marc Glisse <marc.glisse@inria.fr> writes:
> 
>> On Tue, 30 Aug 2011, Ian Lance Taylor wrote:
>>
>>> Jonathan Wakely <jwakely.gcc@gmail.com> writes:
>>>
>>>> You could file an enhancement request in Bugzilla requesting that the
>>>> warning is disabled for the variable in the for-range-declaration.
>>>
>>> Personally I think this is the way to go.  The variable is implicitly
>>> used, and the warning should reflect that.
>>
>> If C++ had allowed for(int:range) in addition to for(int i:range),
>> like you can abstain from naming function arguments, the warning would
>> have made more sense. As it is, I agree the warning should go,
>> although I don't know why you say the variable is implicitly used.
> 
> The variable is implicitly used in the generated code: each element of
> the iterable is assigned to it in turn.  Those assignments are likely
> later discarded as dead, but there is still an implicit use.

But an assignment is considered a def (rather than a use) by that warning.
Isn't it?

Andrew.