https://issues.dlang.org/show_bug.cgi?id=24841

          Issue ID: 24841
           Summary: UTF-16 surrogates when used as an escape of a string
                    should hint on error
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: alphaglosined@gmail.com

UTF-16 has some special ranges assigned to it known as surrogates.

If they appear as a dchar it is rightly an error.

The lexer should when it sees this range, should error but hint that what you tried to escape was the wchar's as if they were dchar's.

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