Re: [boost] error_code and error_category problem

From: Christopher Kohlhoff (chris_at_[hidden])
Date: 2008-07-01 08:35:53

Berserker wrote:
> In my project (using asio) I have something like this:
> 
> void Foo::myCallback(const boost::system::error_code &e)
> {
>      if(e == boost::asio::error::operation_aborted)
>      {
>          // bla bla...
>      }
> }
> 
> This call is made across a shared dll and I notice that for a "strange" reason e == boost::asio::error::operation_aborted was always false.
> 
> I discover that when the temporary object boost::system::error_code is constructed from the constants boost::asio::error::operation_aborted  the error_code's costructor take a pointer to a "error_category" and the comparison operator is (m_cat is an error_category pointer):
> 
> inline friend bool operator==( const error_code & lhs, const error_code & rhs )
> {
>     return lhs.m_cat == rhs.m_cat && lhs.m_val == rhs.m_val;
> }
> 
> In my situation (using shared modules) lhs.m_cat == rhs.m_cat points to differents memory regions (even if are of the same type "system_category") because of the static initialization in the function "get_system_category".

Are you using the dll version of boost_system? You need to so that there 
will only be one copy of the get_system_category function.

Cheers,
Chris

P.S. please don't mail to both lists separately -- it made your emails 
get flagged as spam for me.