More flexible sorted ranges?

[Xinok via Digitalmars-d-learn]

On Sunday, 2 November 2014 at 15:13:37 UTC, bearophile wrote:
> I have often arrays that are sorted, and sometimes I'd like to 
> append items to them. So I'd like to write something like:
>
>
> SortedRange!(Foo[], q{ a.x < b.x }) data;
> data ~= Foo(5);
> immutable n = data.upperBound(Foo(2)).length;
>
>
> This means having an array of Foos as sorted range, and 
> appending an item to it keeping the sorting invariant (so in 
> non-release mode the append verifies the array is empty or the 
> last two items satisfy the sorting invariant), and this allows 
> me to call functions like upperBound any time I want on 'data' 
> without using any unsafe and unclean assumeSorted.
>
> Is this possible and a good idea to do?
>
> Bye,
> bearophile

My concern is that SortedRange only accepts a range which is 
random-access and limits its functionality to those primitives. 
Concatenation is not required for random-access ranges, so should 
we expect SortedRange to overload this operator?