Re: Explanation of Octave operator overloading

[John Swensen]

John W. Eaton wrote:
> On  5-May-2006, John Swensen wrote:
>
> | Thanks for pointing me in the right direction.  That example gave me
> | exactly what I needed.  I did find, however, that for simple comparison
> | operations, there are macros to make it *really* easy.  The DEFBINOP_OP
> | macro allows you to simply implements an accesor function in the
> | user-defined type to return some integer value that can then be compared
> | against other octave types.  In my case, I have a octave_socket class.
> | I used the DEFBINOP_OP macro as follow:
> | DEFBINOP_OP (lt, scalar, scalar, <)
> | DEFBINOP_OP (le, scalar, scalar, <=)
> | DEFBINOP_OP (eq, scalar, scalar, ==)
> | DEFBINOP_OP (ge, scalar, scalar, >=)
> | DEFBINOP_OP (gt, scalar, scalar, >)
> | DEFBINOP_OP (ne, scalar, scalar, !=)
> | 
> | I then had to overload the scalar_value() method in my user-defined type
> | and now I can compare against integers with all the operators.
>
> Do you really need to create a new data type for these functions (and
> by "these functions" I mean the normal Unix connect, accept, bind,
> listen, etc.)?  Can't you just use an integer for the socket file
> descriptor and a structure for the socket address?
>
> jwe
>
>
>   
I could just use an integer.  In fact, really the only member variable
is a socket file descriptor.  The nice thing, IMO, is the fact that by
defining a new type, sockets get cleaned up nicely when the
octave_socket variable goes out of scope.  If you want me to change this
before I submit it for approval, I am willing (and it shouldn't be too
hard).  Just let me know if you would prefer me to do it your way.

John Swensen