Make certain functions pure virtual so I won't forget to implement them

[libs/core.git] / source / io / slice.h

diff --git a/source/io/slice.h b/source/io/slice.h
index f6115851c4c4c0637dcc262191c15e51cdcec81c..fb4501483bd56e0956ac9b6775d352b53d2ad508 100644 (file)
--- a/source/io/slice.h
+++ b/source/io/slice.h
@@ -16,7 +16,7 @@ its range.  If the offset of the underlying object is changed, the Slice will
 restore it before the next access.  This enables multiple Slices to be created
 on top of the same object.
 */
-class Slice: public Seekable
+class Slice: public Seekable, public sigc::trackable
 {
 private:
        Seekable &below;
@@ -28,6 +28,8 @@ private:
 public:
        Slice(Seekable &, SeekOffset, SeekOffset);
 
+       virtual void set_block(bool);
+
 private:
        void flush();
 
@@ -40,6 +42,8 @@ public:
        virtual unsigned put(char);
        virtual int get();
 
+       virtual const Handle &get_handle(Mode);
+
        virtual SeekOffset seek(SeekOffset, SeekType);
        virtual SeekOffset tell() const { return position; }
 };