Re: [boost] Strings and thread safety

From: Felipe Magno de Almeida (felipe.m.almeida_at_[hidden])
Date: 2006-09-08 11:51:07

On 9/8/06, Jeff Garland <jeff_at_[hidden]> wrote:

> > [snipped]

> >
> > There's something I want to clear out, lexical_cast is reentrant and only
> > uses "stacked" variables no ?
>
> So what?  Those stack types are free to reference global data. And in the case
> of stringstream, in combination with operators<< and operator>>, they most
> certainly do access global data in the form of locales and facets.

But I believe almost every STL implementation has thread-safe
iostreams, with locked access to global locales and etc. I know that
VC 7.1 and STLPort has. Without it, it is almost impossible to write
thread correct C++ programs. Or am I missing something?

> [snipped]

> The real problem here, is that lexical_cast *will work* most of the time in an
> MT environment without difficulty. But that's not good enough to declare it
> 'thread-safe'...which is the entire assumption in this thread.  Actually, as
> this whole discussion illustrates, it's probably enough to make it
> 'thread-dangerous' ;-)

It is only thread-safe if what it uses has the basic thread-safety
guarantees. Which, for all I know, it is true in every implementation
that cares about writing thread-safe programs.

>
> Jeff

best regards,
-- 
Felipe Magno de Almeida