pure and custom new / delete

[Steven Schveighoffer]

On Tue, 26 Jun 2012 14:08:14 -0400, Benjamin Thaut  
<code at benjamin-thaut.de> wrote:


> Thanks this works, but it seems to be a very ugly hack just to work  
> around the type system. Also I have templated allocator functions I can  
> not use this trick on. This is going to be a lot of work to get done  
> properly, so I just ignore pure for now I think.

Um... yeah :)  If you are working around the type system, it *should* be  
ugly!

Note that you should be *extremely* careful of saying something is pure  
when it is not typechecked by the compiler.  If I were designing such an  
allocator system, I'd separate out pure and impure allocators into two  
separate hierarchies, and let the person implementing the actual  
underlying allocator jump the fence between pure and impure.

For example, in the code I gave, really only C malloc should be  
forced-pure, everything else should be typechecked as pure by the  
compiler.  But you were asking for a specific solution.

-Steve