Re: Ada Annoyances

[pythoner6@gmail.com]

On Wednesday, June 21, 2017 at 12:12:53 PM UTC-4, Dmitry A. Kazakov wrote:
> In Ada there is no penalty of calling a "method" vs. a "free" function. 
> None, whatsoever. This per language type system design and different 
> from C++.

I would say the same is true of C++ -- a method in C++ just has an implicit parameter that would be explicit in Ada (the only potential difference I can think of is that the implicit parameter is always by reference in C++ where Ada may choose to pass it by value, unless as you note you are dealing with a tagged type).

> I don't consider here the overhead of using any helper types/objects 
> and/or class-wide objects. That has nothing to do with the type under 
> consideration being tagged or not.
> 
> The penalty of a tagged type is only this:
> 
> 1. Space to keep the type tag
> 2. By-reference passing only, even if the object is small.
> 
> -- 
> Regards,
> Dmitry A. Kazakov
> http://www.dmitry-kazakov.de

Thanks for the clarifications - as mentioned in my previous post, I think the main misconception I had was about when dynamic dispatch happens: I rather naively assumed that dynamic dispatch happened whenever tagged types were involved. After reading this it sounds like using tagged types in Ada is quite similar to dealing with classes in C++ (i.e. in C++, methods have the implicit this parameter which is also only ever passed by reference). Now that I better understand how tagged types work, I think I don't really mind the restriction.