ElementEncodingType and immutable

[Jonathan M Davis]

On Friday, November 22, 2013 10:17:40 bioinfornatics wrote:
> On Friday, 22 November 2013 at 07:54:45 UTC, Jonathan M Davis
> 
> wrote:
> > On Friday, November 22, 2013 01:01:52 bioinfornatics wrote:
> >> hi with this code: http://www.dpaste.dzfl.pl/2f830da1
> >> I do not understand why alias Char is equal to immutable(char)
> >> 
> >> How to fix these issues?
> > 
> > I'm not quite sure which line you're refering to here, but
> > ElementEncodingType
> > is going to give the same constness as the elements - e.g.
> > ElementEncodingType!string is going to be immutable(char), not
> > char.
> > 
> > Also, you're doing something with AAs, and all keys for AAs are
> > immutable,
> > even if you don't explicitly mark them as immutable, so if if
> > the type that
> > you're using ElementEncodingType was a key in an AA, that could
> > be your
> > problem.
> > 
> > However, the first error that's popping up seems to relate to
> > the fact that
> > ranges treat strings as ranges of dchar, not char, so sequence
> > gives you
> > letters which are dchar, not char, and then you try and assign
> > it to an AA
> > which holds immutable(char) rather than dchar (and the fact
> > that the AA holds
> > immutable(char) rather than char might cause further problems
> > with being able
> > to reassign anything in the AA - and if it doesn't it's
> > probably due to the AA
> > doing casting internally when it shouldn't).
> > 
> > - Jonathan M Davis
> 
> Thanks Jonathan
> 
> I try to have a dynamic type
> If sequence is immutable(char)[] AA become char[ubyte]
> If sequence is immutable(dchar)[] AA become dchar[ushort] …

Then you can't put sequence in a range and get its value out from there. 
immutable(char)[]will be treated as a range of dchar, so you'll get dchars, 
not chars. If you want to operate on a string as chars, then don't use it as a 
range. The closest that you could get to operating on it as a range of chars 
would be to use std.string.representation and operate on it as 
immutable(ubyte)[].

- Jonathan M Davis