"Justin M. Lewis" wrote: > > in/out seems to be used fairly commonly in COM. I'm not sure I have any > great examples off the top of my head, but I know they're commonly used.
I'm not a COM person, but I believe it's written in C. If so, then you are correct that in/out parameters are more needed since noone would want to create a struct for each multiple return type. OTOH, C++ has templates to deal with this situation (ie boost::tuple<>) so, qualifying my previous statement, in C++ I still see no need for in/out parameters. > And using pointers is part of what we're trying to avoid here. Like I said, > I avoid using pointers whenever possible at this point. I'm a little confused. Either you pass in the entire object or you pass in a pointer (even if it's wrapped in another class). How is this new class supposed to be implemented? > And, again, the real intent here is to insure clarity at the point of > invocation. In my case I'm looking at 100's of thousands of lines of code, > written over the past 8 years. It's tiresome trying to chase down where > values COULD have changed. In this setup you KNOW exactly what calls are > changing parameter values, and it's enforced. As long as the library calls > use the c_out and c_in_out classes people using the library are forced to > conform to the format. So, 8 years, and a few million lines of code later, > no one will wonder what might cause a variable they're tracking to change > values. I think if parameters are used for in parameters only and return values are used for out parameters only, the same thing is achieved. For example, inOutValue = square( inOutValue ); vs (using an extension for generality): square( c_in_out< typeof( inOutValue ) >( inOutValue ) ); Noel _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
