https://issues.dlang.org/show_bug.cgi?id=21463

          Issue ID: 21463
           Summary: std.typecons.Proxy declares opCmp when it should not
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: phobos
          Assignee: nobody@puremagic.com
          Reporter: tobias@pankrath.net

--
import std.typecons : Proxy;

struct Inner {}
class Outer
{
    Inner inner;
    mixin Proxy!inner;
}

int main() { return 0; }
--

> /usr/include/dlang/dmd/std/typecons.d(6762): Error: need member function opCmp() for struct Inner to compare

--