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From: williamkempf_at_[hidden]
Date: 2001-03-15 13:18:39

--- In boost_at_y..., "E. Karpachov" <jk_at_s...> wrote:
> On Thu, Mar 15, 2001 at 05:01:06PM -0000, williamkempf_at_h... wrote:
> > I will *NOT* throw an exception containing an errno value. Such
> > value is not portable (the errnos returned by various thread APIs
> (By the way, it is portable as far as POSIX is - but I can
understand that
> POSIX portability is not sufficient.)


> > will not match) and so will not be useful to programmers. If the
> > specific type of error that occurred is necessary (I'm not sure
it is
> > in most cases) then we either need to define our own errnos, or
> > preferrably throw different exceptions (or at least change the
> > text accordingly).
> Yes, but you could at least incapsulate POSIX errno or some other
> system-dependent error information deep inside of exception class,
> separate implementation-defined part. Something like
> class base_thread_error : public std::runtime_error { // or
> public:
> // ...
> virtual const char *what() const;
> impl_errno *error_code() const;
> private:
> struct impl_errno *error_code_;
> // ...
> };

You miss the problem here. Yes, I could expose an errno that
implementation specific here. But it's pointless in a portable
sense, since it IS implementation specific. Client code can not make
use of the errno in a portable manner. If the specific errno is
useful to know (debatable in this context) than it must be translated
into a portable bit of information. I will *NOT* expose
implementation specific errnos on the interface here. Portable ones,

Bill Kempf

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