Re: [boost] [function] Placement new warnings from gcc 6

Subject: Re: [boost] [function] Placement new warnings from gcc 6
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2016-04-04 03:52:45

On 2016-04-04 04:35, Gavin Lambert wrote:
> On 3/04/2016 02:08, Andrey Semashev wrote:
>> I guess, I could extract all members other than 'data' to a separate
>> union and then:
>>
>>    union function_buffer
>>    {
>>      mutable function_buffer_members m;
>>      mutable char data[sizeof(function_buffer_members)];
>>    };
>>
>> This would require more modifications to the code though.
>>
>> (Sigh... if only we could inherit unions...)
>
> Could you do this with an anonymous union?  eg:
>
> union function_buffer
> {
>     mutable union function_buffer_members
>     {
>         ...
>     };
>     mutable char data[sizeof(function_buffer_members)];
> };
>
> Haven't tested this; not sure if it's legal to get the sizeof a subtype
> nested in the same scope like this, but it at least seems plausible.

That is a named union in your example. And if it's anonymous then you 
have no name to apply sizeof to.