Made the default distances of sample_pair and ordered_sample_pair objects

1 instead of infinity.

dlib/graph_utils/ordered_sample_pair.h

@@ -20,7 +20,7 @@ namespace dlib
             _index1(0),
             _index2(0)
         {
-            _distance = std::numeric_limits<double>::infinity();
+            _distance = 1;
         }
 
         ordered_sample_pair (
@@ -28,7 +28,7 @@ namespace dlib
             const unsigned long idx2
         )
         {
-            _distance = std::numeric_limits<double>::infinity();
+            _distance = 1;
             _index1 = idx1;
             _index2 = idx2;
         }

dlib/graph_utils/ordered_sample_pair_abstract.h

@@ -30,7 +30,7 @@ namespace dlib
             ensures
                 - #index1() == 0
                 - #index2() == 0
-                - #distance() == std::numeric_limits<double>::infinity()
+                - #distance() == 1 
         !*/
 
         ordered_sample_pair (
@@ -41,7 +41,7 @@ namespace dlib
             ensures
                 - #index1() == idx1
                 - #index2() == idx2
-                - #distance() == std::numeric_limits<double>::infinity()
+                - #distance() == 1 
         !*/
 
         ordered_sample_pair (

dlib/graph_utils/sample_pair.h

@@ -20,7 +20,7 @@ namespace dlib
             _index1(0),
             _index2(0)
         {
-            _distance = std::numeric_limits<double>::infinity();
+            _distance = 1;
         }
 
         sample_pair (
@@ -28,7 +28,7 @@ namespace dlib
             const unsigned long idx2
         )
         {
-            _distance = std::numeric_limits<double>::infinity();
+            _distance = 1;
             if (idx1 < idx2)
             {
                 _index1 = idx1;

dlib/graph_utils/sample_pair_abstract.h

@@ -34,7 +34,7 @@ namespace dlib
             ensures
                 - #index1() == 0
                 - #index2() == 0
-                - #distance() == std::numeric_limits<double>::infinity()
+                - #distance() == 1 
         !*/
 
         sample_pair (
@@ -45,7 +45,7 @@ namespace dlib
             ensures
                 - #index1() == min(idx1,idx2)
                 - #index2() == max(idx1,idx2)
-                - #distance() == std::numeric_limits<double>::infinity()
+                - #distance() == 1 
         !*/
 
         sample_pair (