June 30, 2018
https://issues.dlang.org/show_bug.cgi?id=19043

          Issue ID: 19043
           Summary: Incorrect mangling for extern(C++) const template
                    parameter on windows
           Product: D
           Version: D2
          Hardware: x86
                OS: Windows
            Status: NEW
          Severity: blocker
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: iamthewilsonator@hotmail.com

struct __dslice(T) {}

extern(C++) void test18716c(__dslice!(const(char)));

is mangled as

    ?test18716b@@YAXU?$__dslice@D@@@Z

instead of

   ?test18716c@@YAXU?$__dslice@$$CBD@@@Z

which is the mangling for

extern(C++) void test18716c(__dslice!(char));

This is a blocker for the fix for issue 18716

--