• via Digitalmars-d-bugs (25/25) Jul 12 2016 https://issues.dlang.org/show_bug.cgi?id=16271

via Digitalmars-d-bugs <digitalmars-d-bugs puremagic.com> writes:

https://issues.dlang.org/show_bug.cgi?id=16271

          Issue ID: 16271
           Summary: Should be able to express that a lambda returns by
                    reference
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: dmd
          Assignee: nobody puremagic.com
          Reporter: andrei erdani.com

This literal takes one parameter by ref and the other by value, and returns by
value:

(ref x, y) { x += y; return x; }
function (ref x, y) { x += y; return x; } // alternative

There is no way to specify that we want it to return e.g. x by reference. These
syntaxes do not work:

function ref (ref x, y) { x += y; return x; }
function ref typeof(x) (ref x, y) { x += y; return x; }

I think the first one should work. For that, the "return" attribute will also
be deduced.

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