IMark doesn't need relational operators

Change-Id: Iea795980626b09a227f8fda59f0065d5dbb1ac24
Reviewed-on: https://gerrit.libreoffice.org/72986
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

sw/inc/IMark.hxx

@@ -22,7 +22,6 @@
 #include <vcl/keycod.hxx>
 #include "calbck.hxx"
 #include "pam.hxx"
-#include <boost/operators.hpp>
 #include <map>
 #include <memory>
 #include "swdllapi.h"
@@ -37,7 +36,6 @@ namespace sw { namespace mark
 
     class SW_DLLPUBLIC IMark
         : virtual public sw::BroadcastingModify // inherited as interface
-        , public ::boost::totally_ordered<IMark>
     {
         protected:
             IMark() = default;
@@ -59,12 +57,6 @@ namespace sw { namespace mark
             // inside core, you can cast to MarkBase and use its setters,
             // make sure to update the sorting in Markmanager in this case
 
-            //operators and comparisons (non-virtual)
-            bool operator<(const IMark& rOther) const
-                { return GetMarkStart() < rOther.GetMarkStart(); }
-            bool operator==(const IMark& rOther) const
-                { return GetMarkStart() == rOther.GetMarkStart(); }
-
             virtual OUString ToString( ) const =0;
             virtual void dumpAsXml(xmlTextWriterPtr pWriter) const = 0;
         private: