Re: [boost] [algorithm][hex] function hex_char_to_int in unnamed namespace in header file

Subject: Re: [boost] [algorithm][hex] function hex_char_to_int in unnamed namespace in header file
From: Felipe Magno de Almeida (felipe.m.almeida_at_[hidden])
Date: 2012-11-27 14:53:19

On Tue, Nov 27, 2012 at 5:41 PM, Marshall Clow <mclow.lists_at_[hidden]> wrote:
> On Nov 27, 2012, at 9:55 AM, Felipe Magno de Almeida <felipe.m.almeida_at_[hidden]> wrote:
>
>> Hello,
>>
>> AFAIK, unnamed namespaces are dangerous in headers. There is a
>> commentary just above the function definition:
>>
>> // this needs to be in an un-named namespace because it is not a template
>> // and might get included in several compilation units. This could cause
>> // multiple definition errors at link time.
>>
>> But it seems the better thing would be to define it inline. It is
>> exactly because it can be used in several
>> translation units that it can cause an ODR violation if defined
>> in a unnamed namespace AFAIK.
>
> I have no problem with declaring it inline, but that's just a suggestion.
> The compiler is completely free to generate code for it out-of-line.

I didn't meant I want the function to be inlined by the compiler. What I mean
is that putting it in a unnamed namespace causes undefined behavior(AFAIK).
So, the solution to being used by multiple translation units should be
to declare
it inline, and not use an unnamed namespace.

> -- Marshall
>
> Marshall Clow     Idio Software   <mailto:mclow.lists_at_[hidden]>
>
> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait).
>         -- Yu Suzuki

Regards,
-- 
Felipe Magno de Almeida