The Status of Const

[Justin Johansson]

Nick Sabalausky wrote:
> "Justin Johansson" <no at spam.com> wrote in message 
> news:i42ba3$1br$1 at digitalmars.com...
>> Nick Sabalausky wrote:
>>> "Justin Johansson" <no at spam.com> wrote in message 
>>> news:i424ac$27nb$1 at digitalmars.com...
>>>> Graham St Jack wrote:
>>>>> Is there any plan to introduce some way of having a mutable reference 
>>>>> to an immutable class object on the heap? Do others see this as a 
>>>>> problem at all?
>>>> For embedded microsystems (i.e. with ROM/RAM) this is a problem.  It
>>>> is a common use case to have a mutable reference (in RAM) to some
>>>> objects that reside in ROM.  Obviously anything in ROM is guaranteed
>>>> by hardware to be immutable.  So, yes, this is a problem in a
>>>> wider sense.
>>> Would there every really be anything in ROM though that would be 
>>> appropriate as a class though, as opposed to, say, a struct? I've never 
>>> heard of an object with a vtable being stored in ROM.
>> Yes, well back in my embedded C++ days yes did so.  But just because I
>> did doesn't necessarily make it a common use case.  Strike 'common'
>> above and replace with 'valid.
>>
> 
> Interesting.
> 
>> Anyway, what about a mutable reference to an immutable struct (in ROM)?
> 
> Since structs are value types in D, wouldn't a reference to it (mutable or 
> otherwise) *have* to be a pointer?
> 
> 
> 

Probably you are right.  I was mainly talking in general terms about
embedded systems (ROM/RAM architectures) and with C++ experience
in this area.  I have never used D in an embedded environment so
YMMV as far as my comments are concerned.