Re: chunkBy limitation?

[Dmitri via Digitalmars-d-learn]

On Friday, 2 October 2015 at 18:16:59 UTC, Ali Çehreli wrote:
On 10/02/2015 02:21 AM, Dmitri wrote:
> [...]
implementation:
> [...]
Error:
> [...]
function
> [...]
less).SortedRange.groupBy!().groupBy
> [...]
the nested
> [...]
compilation error.
> [...]
Group should
> [...]
This is a known D issue. Currently, objects have a single 
context pointer. Here is a bug discussion about it:

  https://issues.dlang.org/show_bug.cgi?id=5710

A workaround for your example is making less() static, which 
removes its context pointer:

void bar(int[] foo)
{
        import std.algorithm : sort;

        static bool less(int a, int b) // contrived
        {
                return a < b;
        }

        foo.sort!less.groupBy;
}

void main() {}

I've just realized that I don't know how to handle the case 
where less() really needs some other state (e.g. it may need to 
use a local variable in main). What can we do?

Ali

Thanks, Ali - this is helpful. The problem was figuring out what 
exactly is wrong given a bunch of unhelpful error messages. A 
somewhat better message comes when using a unary predicate 
version of chunkBy.