https://issues.dlang.org/show_bug.cgi?id=23865

          Issue ID: 23865
           Summary: duplicate alias not detected
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: minor
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: nick@geany.org

class AssignableRange
    {
        int element;
        int front()
        {
            return element;
        }
        alias back = front;

        void front(int newValue)
        {
            element = newValue;
        }
        alias back = front;
    }

`back` is aliased twice. It still doesn't error if the second alias is changed to target `element`.

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