Re: [boost] [fusion] sequence io manipulators

Subject: Re: [boost] [fusion] sequence io manipulators
From: Jeff Flinn (Jeffrey.Flinn_at_[hidden])
Date: 2013-03-27 10:28:56

On 3/27/2013 9:03 AM, Jeff Flinn wrote:
> On 3/26/2013 4:01 PM, Eric Niebler wrote:
>> On 13-03-26 10:46 AM, Steven Watanabe wrote:
>>> AMDG
>>>
>>> On 03/26/2013 10:03 AM, Jeff Flinn wrote:
>>>>
>>>> I have not addressed possible issues with "static int index =
>>>> std::ios::xalloc();" thread safety. gcc at least appears to guard this
>>>> initialization with a mutex. I'm not sure what the standard guarantees
>>>> in this regard pre/post C++11. Comments would be appreciated.
>>>
>>> C++11 guarantees that function statics are
>>> thread safe.  C++03 doesn't.
>>
>> Right. And IIRC, different versions of different compilers implemented
>> that C++11 feature at different times, so it can't really be relied on
>> in portable code. Yet.
>
> I checked and found fusion, tuple, locale libs all obtain an index from
> xalloc using local static initialization.
>
> chrono and units libs use class static member initialization. I'll
> prepare a patch to update fusion you use this latter initialization.

I've updated the patch in Ticket# 8336 using Steven's static 
initialization approach from units io.hpp.

Jeff