Make one-time comparator a lambda.

Author: egorpugin

src/ccstruct/polyblk.cpp

@@ -34,8 +34,6 @@ namespace tesseract {
 
 #define INTERSECTING INT16_MAX
 
-int lessthan(const ICOORDELT *first, const ICOORDELT *second);
-
 POLY_BLOCK::POLY_BLOCK(ICOORDELT_LIST *points, PolyBlockType t) {
   ICOORDELT_IT v = &vertices;
 
@@ -357,7 +355,15 @@ ICOORDELT_LIST *PB_LINE_IT::get_line(TDimension y) {
   }
 
   if (!r.empty()) {
-    r.sort(lessthan);
+    r.sort([](const ICOORDELT *p1, const ICOORDELT *p2) {
+      if (p1->x() < p2->x()) {
+        return (-1);
+      } else if (p1->x() > p2->x()) {
+        return (1);
+      } else {
+        return (0);
+      }
+      });
     for (r.mark_cycle_pt(); !r.cycled_list(); r.forward()) {
       x = r.data();
     }
@@ -371,16 +377,6 @@ ICOORDELT_LIST *PB_LINE_IT::get_line(TDimension y) {
   return result;
 }
 
-int lessthan(const ICOORDELT *p1, const ICOORDELT *p2) {
-  if (p1->x() < p2->x()) {
-    return (-1);
-  } else if (p1->x() > p2->x()) {
-    return (1);
-  } else {
-    return (0);
-  }
-}
-
 #ifndef GRAPHICS_DISABLED
 /// Returns a color to draw the given type.
 ScrollView::Color POLY_BLOCK::ColorForPolyBlockType(PolyBlockType type) {