Re: [boost] [Endian] Performance

Subject: Re: [boost] [Endian] Performance
From: John Filo (filo_at_[hidden])
Date: 2011-09-09 08:53:30

On 09/09/2011 03:29 AM, Mathias Gaunard wrote:
> On 07/09/2011 14:16, John Filo wrote:
>
>> I.e. I added:
>>
>> #elif USE_BIG
>> return *reinterpret_cast<const ubig32_t*>(&src);
>> #elif USE_LITTLE
>> return *reinterpret_cast<const ulittle32_t*>(&src);
>> #elif USE_NATIVE
>> return src;
>
> This breaks aliasing rules.

I wondered about that; I assumed that since the return statement was the 
only memory read from memory in the function, and that there were no 
writes that aliasing wouldn't be a problem.  Also, I had -Wall on and 
GCC didn't complain, so I assumed it was okay. I guess I need to read up 
on what the exact rules are.