calling syntax (was Re: Ada Objects)

[nebbe@lglsun.epfl.ch (Robb Nebbe)]

In article <3flk3r$8qj@gdls.com>, wilkinso@gdls.com (Robert M. Wilkinson) writes:
|> In article <D2H5un.FEr@nntpa.cb.att.com>,
|> Kenneth Almquist <ka@socrates.hr.att.com> wrote:
|> >
|> >C++ has two procedure calling syntaxes.  It is possible to write either
|> >   display(myptr);
|> >or
|> >   myptr->display();
|>  
|> Please note that these have *entirely* different semantics; they are not
|> merely "two forms of syntax" for the same thing. 
|>  

I'm not sure you would want to call this a semantic difference. The
semantics are the operation display is called with the parameter
myptr in both cases. The real difference is in the implementation. The
first is just a normal function call like you would find in C (or Ada)
in the second the parameter is called "this" inside the function
and if it is virtual (and the compiler can't be sure exactly what the
pointer points at) then the implementation will be chosen at run-time,
otherwise it is called just like a normal function.

Robb Nebbe