Head Const

[Ola Fosheim Grøstad via Digitalmars-d]

On Wednesday, 17 February 2016 at 19:03:25 UTC, Jonathan M Davis 
wrote:
> As soon as you start using pointers or containers or pointers 
> or anything like that, pretty quickly, you can get situations 
> like where the container is const, but its elements aren't.

Yes, generic containers is an issue in C++. You can't just recast 
the template parameter as const, as the internals could depend on 
it not being const when the container was instantiated (if-test 
on const in the constructor). This is a problem we get when 
meta-programming becomes powerful enough.

The easy way out is to use a wrapper and implement the constness 
in the wrapper (a class with just a pointer and methods). 
Basically implement a reference type for container access.