structs vs classes

[Jim]

Simen kjaeraas Wrote:

> Jim <bitcirkel at yahoo.com> wrote:
> 
> 
> > "All class-based objects are dynamically allocated—unlike in C++, there  
> > is no way to allocate a class object on the stack."
> > - The D Programming Language, chapter 6.
> 
> That would probably be better written as "there is no built-in way to
> allocate a class object on the stack." D is a pragmatic system programming
> language. If you want to treat this blob of memory as a Foo, and you're
> willing to jump through some hoops, it can be done. But the language does
> not encourage this.
> 
> Like I said, putting a class on the stack is an unsafe thing to do (see
> http://en.wikipedia.org/wiki/Object_slicing), and it was deemed that the
> language should not directly support such an idiom. It is still doable in
> a library.
> 
> 
> > The lightweight nature of structs is very appealing though. I like that  
> > very much of course. Couldn't that be optimised by the compiler alone  
> > knowing that a class wasn't derived?
> 
> Perhaps, in some cases. Final classes might. If a class is not marked
> final, someone might derive from it, include this from a DLL or otherwise,
> and boom goes the program.
> 
> -- 
> Simen

Okay, thanks! I learned some from this thread.