http://wiki.dlang.org/DIP25

[Steven Schveighoffer via Digitalmars-d]

On 12/28/14 4:33 PM, Walter Bright wrote:
> On 12/28/2014 12:04 PM, Peter Alexander wrote:
>> On Sunday, 28 December 2014 at 18:16:04 UTC, Andrei Alexandrescu wrote:
>>> Very little breakage I can think of. Ranges usually don't own their
>>> payload.
>>
>> I'm thinking more about higher order ranges, e.g. take, filter, cycle,
>> retro;
>> over a mutable range with ref front. Even if the underlying range
>> (e.g. an
>> array) has the inout, the higher order range will need the inout as
>> well, so
>> that it is propagated, no?
>
> inout is not transitive, so a ref on the container doesn't apply to a
> ref on the contents if there's another level of indirection in there.
>

I'm not sure what you mean by this, but inout as a type modifier is 
definitely transitive.

-Steve