From c7e8f2a3e3b06409b2a8627935570af43ef1dace Mon Sep 17 00:00:00 2001
From: Your Name <y@maps.me>
Date: Wed, 9 Aug 2017 15:40:58 +0300
Subject: [PATCH] Review fixes.

---
 search/features_layer_matcher.hpp          |  3 +--
 search/point_rect_matcher.hpp              |  9 +++++----
 search/search_tests/segment_tree_tests.cpp |  6 +++---
 search/segment_tree.cpp                    |  2 +-
 search/segment_tree.hpp                    | 14 ++++++++++----
 5 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/search/features_layer_matcher.hpp b/search/features_layer_matcher.hpp
index 35af53ad0f..0d2392e0ac 100644
--- a/search/features_layer_matcher.hpp
+++ b/search/features_layer_matcher.hpp
@@ -143,8 +143,7 @@ private:
       }
     }
 
-    PointRectMatcher matcher;
-    matcher.Match(poiCenters, buildingRects, [&](size_t poiId, size_t buildingId) {
+    PointRectMatcher::Match(poiCenters, buildingRects, [&](size_t poiId, size_t buildingId) {
       ASSERT_LESS(poiId, pois.size(), ());
       ASSERT_LESS(buildingId, buildings.size(), ());
       fn(pois[poiId], buildings[buildingId]);
diff --git a/search/point_rect_matcher.hpp b/search/point_rect_matcher.hpp
index b23c439a76..e72daa74e2 100644
--- a/search/point_rect_matcher.hpp
+++ b/search/point_rect_matcher.hpp
@@ -31,13 +31,14 @@ public:
     size_t m_id = 0;
   };
 
-  // Finds matching between |points| and |rects|, calls |fn| on
-  // matched pairs.
+  // For each point tries to find a rect containing the point. If
+  // there are several rects containing the point, selects an
+  // arbitrary one. Calls |fn| on matched pairs (point-id, rect-id).
   //
   // Complexity: O(n * log(n)), where n = |points| + |rects|.
   template <typename Fn>
-  void Match(std::vector<PointIdPair> const & points, std::vector<RectIdPair> const & rects,
-             Fn && fn)
+  static void Match(std::vector<PointIdPair> const & points, std::vector<RectIdPair> const & rects,
+                    Fn && fn)
   {
     std::vector<Event> events;
     events.reserve(points.size() + 2 * rects.size());
diff --git a/search/search_tests/segment_tree_tests.cpp b/search/search_tests/segment_tree_tests.cpp
index 3ebd8f76ee..9e28a574b0 100644
--- a/search/search_tests/segment_tree_tests.cpp
+++ b/search/search_tests/segment_tree_tests.cpp
@@ -40,9 +40,9 @@ UNIT_TEST(SegmentTree_Smoke)
 
 UNIT_TEST(SegmentTree_Simple)
 {
-  vector<Segment> segments = {Segment(-10000, -10000, 0 /* id */), Segment(-10, -6, 1 /* id */),
-                              Segment(-5, -2, 2 /* id */)};
-  TEST(is_sorted(segments.begin(), segments.end()), ());
+  vector<Segment> segments = {Segment(-10000 /* from */, -10000 /* to */, 0 /* id */),
+                              Segment(-10, -6, 1), Segment(-5, -2, 2)};
+  CHECK(is_sorted(segments.begin(), segments.end()), ());
 
   SegmentTree tree(segments);
 
diff --git a/search/segment_tree.cpp b/search/segment_tree.cpp
index b254cdf318..3cc2f68a02 100644
--- a/search/segment_tree.cpp
+++ b/search/segment_tree.cpp
@@ -24,8 +24,8 @@ size_t CeilPow2Minus1(size_t n)
 
 SegmentTree::SegmentTree(vector<Segment> const & segments) : m_tree(CeilPow2Minus1(segments.size()))
 {
-  BuildTree(0 /* index */, segments, 0 /* left */, m_tree.size() /* right */);
   ASSERT(is_sorted(segments.begin(), segments.end()), ());
+  BuildTree(0 /* index */, segments, 0 /* left */, m_tree.size() /* right */);
 }
 
 void SegmentTree::Add(Segment const & segment)
diff --git a/search/segment_tree.hpp b/search/segment_tree.hpp
index 8d0cf82e27..adc85a1834 100644
--- a/search/segment_tree.hpp
+++ b/search/segment_tree.hpp
@@ -15,9 +15,9 @@ namespace search
 class SegmentTree
 {
 public:
-  double static constexpr kNegativeInfinity = -std::numeric_limits<double>::max();
-  double static constexpr kPositiveInfinity = std::numeric_limits<double>::max();
-  size_t static constexpr kInvalidId = std::numeric_limits<size_t>::max();
+  auto static constexpr kNegativeInfinity = -std::numeric_limits<double>::max();
+  auto static constexpr kPositiveInfinity = std::numeric_limits<double>::max();
+  auto static constexpr kInvalidId = std::numeric_limits<size_t>::max();
 
   struct Segment
   {
@@ -47,8 +47,14 @@ public:
 
   struct Node
   {
+    // Segment corresponding to the node.
     Segment m_segment;
+
+    // Maximum value among all right bounds of non-deleted segments in
+    // the subtree.
     double m_to = kNegativeInfinity;
+
+    // True when corresponding segment is deleted.
     bool m_deleted = true;
   };
 
@@ -58,7 +64,7 @@ public:
   void Add(Segment const & segment);
   void Erase(Segment const & segment);
 
-  // Calls |fn| on any segment containing |x|.
+  // Calls |fn| on arbitrary segment containing |x|.
   template <typename Fn>
   void Find(double x, Fn && fn) const
   {