[Boost-users] error_code and error_category problem

From: Berserker (berserker_r_at_[hidden])
Date: 2008-06-13 04:29:22

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".
The problem exist in the comparison operator of error_category too:

bool operator==(const error_category & rhs) const { return this == &rhs; }

I suggest to change the comparison criteria (for example using an enumerated value)

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