Re: [Boost-users] shared_ptr problems

From: Peter Dimov (pdimov_at_[hidden])
Date: 2005-11-03 13:24:58

Filipe Sousa wrote:

> int main()
> {
>  {
>    Connection c = ConnectionManager::instance()->connection();
>    std::clog << "isConnected " << c.isConnected() << std::endl;
>    c.connect();

This initializes the shared_ptr inside c, but has no effect on the 
shared_ptr in the ConnectionManager map.

>    std::clog << "isConnected " << c.isConnected() << std::endl;

     std::clog << "isConnected " << 
ConnectionManager::instance()->connection().isConnected() << std::endl;

>  }

'c' is destroyed here, along with its shared_ptr, which calls mysql_close.

>  Connection c = ConnectionManager::instance()->connection();
>  std::clog << "isConnected " << c.isConnected() << std::endl;
>
>  return 0;
> }

You need to .reset( .. ) the shared_ptr in the map, before returning it from 
the connection manager.