--- a/liboctave/idx-vector.h
+++ b/liboctave/idx-vector.h
@@ -29,6 +29,7 @@
 
 class ostream;
 class ColumnVector;
+class boolMatrix;
 class Matrix;
 class Range;
 
@@ -68,6 +69,10 @@
 
     idx_vector_rep (char c);
 
+    idx_vector_rep (bool b);
+
+    idx_vector_rep (const boolMatrix& bm);
+
     idx_vector_rep (const idx_vector_rep& a);
 
     ~idx_vector_rep (void) { delete [] data; }
@@ -128,7 +133,7 @@
 
     void init_state (void);
 
-    void maybe_convert_one_zero_to_idx (int z_len, int prefer_zero_one);
+    void maybe_convert_one_zero_to_idx (int z_len);
   };
 
 public:
@@ -169,6 +174,18 @@
       rep->count = 1;
     }
 
+  idx_vector (bool b)
+    {
+      rep = new idx_vector_rep (b);
+      rep->count = 1;
+    }
+
+  idx_vector (const boolMatrix& bm)
+    {
+      rep = new idx_vector_rep (bm);
+      rep->count = 1;
+    }
+
   idx_vector (const idx_vector& a)
     {
       rep = a.rep;
@@ -238,8 +255,8 @@
   friend ostream& operator << (ostream& os, const idx_vector& a)
     { return a.print (os); }
 
-  void maybe_convert_one_zero_to_idx (int z_len, int prefer_zero_one = 0)
-    { rep->maybe_convert_one_zero_to_idx (z_len, prefer_zero_one); }
+  void maybe_convert_one_zero_to_idx (int z_len)
+    { rep->maybe_convert_one_zero_to_idx (z_len); }
 
 private: