Remove some duplicate code.

We had a template to compare pairs by their second member, and two
separate classes to do the same thing for specific pair types.  Remove
the non-generic versions, and move the template to libutil.h.

4 files changed, 22 insertions, 37 deletions

diff --git a/crawl-ref/source/effects.cc b/crawl-ref/source/effects.cc
index d57421d1ae..6e98d0e4cf 100644
--- a/crawl-ref/source/effects.cc
+++ b/crawl-ref/source/effects.cc
@@ -2373,19 +2373,6 @@ void update_level(int elapsedTime)
         delete_cloud(i);
 }
 
-// A comparison struct for use in an stl priority queue.
-template<typename T>
-struct greater_second
-{
-    // The stl priority queue is a max queue and uses < as the default
-    // comparison.  We want a min queue so we have to use a > operation
-    // here.
-    bool operator()(const T & left, const T & right)
-    {
-        return left.second > right.second;
-    }
-};
-
 // Basically we want to break a circle into n_arcs equal sized arcs and find
 // out which arc the input point pos falls on.
 static int _arc_decomposition(const coord_def & pos, int n_arcs)
@@ -2459,7 +2446,8 @@ void collect_radius_points(vector<vector<coord_def> > &radius_points,
 
     // Using a priority queue because squares don't make very good circles at
     // larger radii.  We will visit points in order of increasing euclidean
-    // distance from the origin (not path distance).
+    // distance from the origin (not path distance).  We want a min queue
+    // based on the distance, so we use greater_second as the comparator.
     priority_queue<coord_dist, vector<coord_dist>,
                    greater_second<coord_dist> > fringe;
 
diff --git a/crawl-ref/source/libutil.h b/crawl-ref/source/libutil.h
index 22c9daa888..01a2c20ab6 100644
--- a/crawl-ref/source/libutil.h
+++ b/crawl-ref/source/libutil.h
@@ -250,6 +250,17 @@ static inline void swapv(Z &a, Z &b)
     b = tmp;
 }
 
+// A comparator for pairs.
+template<typename T>
+struct greater_second
+{
+    bool operator()(const T & left, const T & right)
+    {
+        return left.second > right.second;
+    }
+};
+
+
 static inline int sqr(int x)
 {
     return x * x;
diff --git a/crawl-ref/source/mon-abil.cc b/crawl-ref/source/mon-abil.cc
index 8415223829..fe4ff0b71d 100644
--- a/crawl-ref/source/mon-abil.cc
+++ b/crawl-ref/source/mon-abil.cc
@@ -1838,31 +1838,23 @@ static bool _lost_soul_affectable(const monster* mons)
            && !mons_class_flag(mons->type, M_NO_EXP_GAIN);
 }
 
-struct hd_sorter
-{
-    bool operator()(const pair<monster* ,int> &a, const pair<monster* ,int> &b)
-    {
-        return a.second > b.second;
-    }
-};
-
 static bool _lost_soul_teleport(monster* mons)
 {
     bool seen = you.can_see(mons);
 
-   vector<pair<monster*, int> > candidates;
+    typedef pair<monster*, int> mon_quality;
+    vector<mon_quality> candidates;
 
     // Assemble candidate list and randomize
     for (monster_iterator mi; mi; ++mi)
     {
         if (_lost_soul_affectable(*mi) && mons_aligned(mons, *mi))
         {
-            pair<monster* , int> m = make_pair(*mi, min(mi->hit_dice, 18)
-                                                    + random2(8));
+            mon_quality m(*mi, min(mi->hit_dice, 18) + random2(8));
             candidates.push_back(m);
         }
     }
-    sort(candidates.begin(), candidates.end(), hd_sorter());
+    sort(candidates.begin(), candidates.end(), greater_second<mon_quality>());
 
     for (unsigned int i = 0; i < candidates.size(); ++i)
     {
diff --git a/crawl-ref/source/spl-other.cc b/crawl-ref/source/spl-other.cc
index 3b2ca4fa7a..f259ae41ca 100644
--- a/crawl-ref/source/spl-other.cc
+++ b/crawl-ref/source/spl-other.cc
@@ -19,6 +19,7 @@
 #include "itemname.h"
 #include "itemprop.h"
 #include "items.h"
+#include "libutil.h"
 #include "makeitem.h"
 #include "message.h"
 #include "misc.h"
@@ -181,14 +182,6 @@ spret_type cast_recall(bool fail)
     return SPRET_SUCCESS;
 }
 
-struct recall_sorter
-{
-    bool operator()(const pair<mid_t,int> &a, const pair<mid_t,int> &b)
-    {
-        return a.second > b.second;
-    }
-};
-
 // Type recalled:
 // 0 = anything
 // 1 = undead only (Yred religion ability)
@@ -196,7 +189,8 @@ struct recall_sorter
 void start_recall(int type)
 {
     // Assemble the recall list.
-    vector<pair<mid_t, int> > rlist;
+    typedef pair<mid_t, int> mid_hd;
+    vector<mid_hd> rlist;
 
     you.recall_list.clear();
     for (monster_iterator mi; mi; ++mi)
@@ -215,7 +209,7 @@ void start_recall(int type)
                 continue;
         }
 
-        pair<mid_t, int> m = make_pair(mi->mid, mi->hit_dice);
+        mid_hd m(mi->mid, mi->hit_dice);
         rlist.push_back(m);
     }
 
@@ -227,7 +221,7 @@ void start_recall(int type)
         // Sort the recall list roughly by HD, randomizing a little
         for (unsigned int i = 0; i < rlist.size(); ++i)
             rlist[i].second += random2(10);
-        sort(rlist.begin(), rlist.end(), recall_sorter());
+        sort(rlist.begin(), rlist.end(), greater_second<mid_hd>());
 
         you.recall_list.clear();
         for (unsigned int i = 0; i < rlist.size(); ++i)