Issue 4550: Avoid "using namespace std;" in included files (Take 2)

lily/note-collision.cc

 /*
   This file is part of LilyPond, the GNU music typesetter.
 
   Copyright (C) 1997--2020 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
 
@@ skipping 15 matching lines @@
 #include "note-head.hh"
 #include "output-def.hh"
 #include "pointer-group-interface.hh"
 #include "item.hh"
 #include "rhythmic-head.hh"
 #include "staff-symbol-referencer.hh"
 #include "side-position-interface.hh"
 #include "stem.hh"
 #include "warn.hh"
 
+using std::vector;
+
 Real
 check_meshing_chords (Grob *me,
                       Grob *clash_up, Grob *clash_down)
 
 {
   /* Every note column should have a stem, but avoid a crash. */
   if (!Note_column::get_stem (clash_up) || !Note_column::get_stem (clash_down))
     return 0.0;
 
   Drul_array<Grob *> stems (Note_column::get_stem (clash_down),
@@ skipping 471 matching lines @@
                        && extents[d][i][DOWN] < extents[d][i - 1][UP])
                 offset += 1.0; // fully clear the previous-notecolumn heads
               else if (d * extents[d][i][-d] >= d * extents[d][i - 1][d])
                 offset += Stem::is_valid_stem (stems[d][i - 1])
                           ? 1.0 : 0.5; // we cross the previous notecolumn
               else if (Stem::is_valid_stem (stems[d][i]))
                 offset += 0.5;
 
               // check if we cross the opposite-stemmed voices
               if (d * extents[d][i][-d] < d * extent_union[-d][d])
-                offset = max (offset, 0.5);
+                offset = std::max (offset, 0.5);
               if (extents[-d].size ()
                   && extents[d][i][UP] > extents[-d][0][DOWN]
                   && extents[d][i][DOWN] < extents[-d][0][UP])
-                offset = max (offset, 1.0);
+                offset = std::max (offset, 1.0);
             }
           offsets[d].push_back (d * offset);
         }
     }
 
   /*
     see input/regression/dot-up-voice-collision.ly
   */
   for (vsize i = 0; i < clash_groups[UP].size (); i++)
     {
@@ skipping 46 matching lines @@
 {
   vector<int> out;
   extract_grob_set (me, "elements", elts);
   for (vsize i = 0; i < elts.size (); i++)
     if (Grob *stem = unsmob<Grob> (elts[i]->get_object ("stem")))
       {
         vector<int> nhp = Stem::note_head_positions (stem);
         out.insert (out.end (), nhp.begin (), nhp.end ());
       }
 
-  vector_sort (out, less<int> ());
+  vector_sort (out, std::less<int> ());
   return out;
 }
 
 ADD_INTERFACE (Note_collision_interface,
                "An object that handles collisions between notes with"
                " different stem directions and horizontal shifts.  Most of"
                " the interesting properties are to be set in"
                " @ref{note-column-interface}: these are @code{force-hshift}"
                " and @code{horizontal-shift}.",
 
                /* properties */
                "merge-differently-dotted "
                "merge-differently-headed "
                "note-collision-threshold "
                "positioning-done "
                "prefer-dotted-right "
               );