https://issues.dlang.org/show_bug.cgi?id=23370

          Issue ID: 23370
           Summary: std.base64 can have more @nogc functions
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: phobos
          Assignee: nobody@puremagic.com
          Reporter: jack@jackstouffer.com

The decoding functions in std.base64 would be automatically marked as @nogc if the functions decodeLength and realDecodeLength were marked @nogc.

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