Kinds of containers

[bitwise via Digitalmars-d]

On Friday, 23 October 2015 at 17:44:55 UTC, deadalnix wrote:

> Sure. We have a problem when it come to collection in the fact 
> that type qualifier do not turtle down as one would expect.
>
> Collection!T and Collection!const(T) are 2 completely different 
> types. There is a good reason for this : static if (is(T == 
> const)) { ... } . As a result thing like :
>
> void foo(T)(const Collection!const(T) c) {}
> void main() {
>   Collection!T c;
>   foo(c); // Error, GTFO !
> }
>
> With the different qualifiers and implicit conversion, thing 
> become quite tricky. You can simulate them partially with a set 
> of carefully crafted alias this (but not having multiple alias 
> this doesn't make things any simpler) but there is the monster 
> of mutually recursive template instanciation that is lurking.
>
> As far as i know, jmdavis had some good work done on this, but 
> it was far from perfect.

Why not just pass a range to foo?