base: reintroduce array::swap.

It merely performs an std::swap() on both array elements, but it’s
apparently convenient to have.

src/lol/algorithm/sort.h

@@ -30,7 +30,7 @@ void array_base<T, ARRAY>::shuffle()
     while (n > 0)
     {
         ni = lol::rand(n--) | 0;
-        std::swap(m_data[ni], m_data[n]);
+        this->swap(ni, n);
     }
 }
 
@@ -59,7 +59,7 @@ void array_base<T, ARRAY>::sort(SortAlgorithm algorithm)
                 d = 1;
             if (m_data[i + 1] < m_data[i])
             {
-                std::swap(m_data[i], m_data[i + 1]);
+                this->swap(i, i + 1);
                 d = -1;
             }
         }
@@ -103,7 +103,7 @@ static void quick_swap_sort(array_base<T, ARRAY> &a,
     {
         if (!(a[i0] < median) && a[i1] < median)
         {
-            std::swap(a[i0], a[i1]);
+            a.swap(i0, i1);
             i0++;
             i1--;
             b_swap = true;

src/lol/base/array.h

@@ -286,6 +286,15 @@ public:
         return tmp;
     }
 
+    inline void swap(ptrdiff_t i, ptrdiff_t j)
+    {
+        ASSERT(i >= 0 && i < m_count && j >= 0 && j < m_count,
+               "cannot swap elements %lld and %lld in array of size %lld",
+               (long long int)i, (long long int)j, (long long int)m_count);
+
+        std::swap(m_data[i], m_data[j]);
+    }
+
     void remove(ptrdiff_t pos, ptrdiff_t todelete = 1)
     {
         ASSERT(todelete >= 0);

src/lol/math/noise/simplex.h

@@ -1,13 +1,14 @@
 //
-// Lol Engine
+//  Lol Engine
 //
-// Copyright: (c) 2010-2014 Sam Hocevar <sam@hocevar.net>
-//            (c) 2013-2014 Benjamin "Touky" Huet <huet.benjamin@gmail.com>
-//            (c) 2013-2014 Guillaume Bittoun <guillaume.bittoun@gmail.com>
-//   This program is free software; you can redistribute it and/or
-//   modify it under the terms of the Do What The Fuck You Want To
-//   Public License, Version 2, as published by Sam Hocevar. See
-//   http://www.wtfpl.net/ for more details.
+//  Copyright: © 2010—2014 Sam Hocevar <sam@hocevar.net>
+//             © 2013—2014 Benjamin "Touky" Huet <huet.benjamin@gmail.com>
+//             © 2013—2014 Guillaume Bittoun <guillaume.bittoun@gmail.com>
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the Do What The Fuck You Want To
+//  Public License, Version 2, as published by Sam Hocevar. See
+//  http://www.wtfpl.net/ for more details.
 //
 
 #pragma once
@@ -94,7 +95,7 @@ protected:
         for (int i = 0; i < N; ++i)
             for (int j = i + 1; j < N; ++j)
                 if (pos[traversal_order[i]] < pos[traversal_order[j]])
-                    std::swap(traversal_order[i], traversal_order[j]);
+                    traversal_order.swap(i, j);
 
 
         /* Get the position in world coordinates, too */

src/t/base/array.cpp

@@ -1,11 +1,12 @@
 //
-// Lol Engine
+//  Lol Engine — unit tests
 //
-// Copyright: (c) 2010-2014 Sam Hocevar <sam@hocevar.net>
-//   This program is free software; you can redistribute it and/or
-//   modify it under the terms of the Do What The Fuck You Want To
-//   Public License, Version 2, as published by Sam Hocevar. See
-//   http://www.wtfpl.net/ for more details.
+//  Copyright: © 2010—2014 Sam Hocevar <sam@hocevar.net>
+//
+//  This program is free software; you can redistribute it and/or
+//  modify it under the terms of the Do What The Fuck You Want To
+//  Public License, Version 2, as published by Sam Hocevar. See
+//  http://www.wtfpl.net/ for more details.
 //
 
 #include <lol/engine-internal.h>
@@ -159,7 +160,7 @@ lolunit_declare_fixture(ArrayTest)
         a.push(10, 20);
         a.push(30, 40);
 
-        std::swap(a[0], a[1]);
+        a.swap(0, 1);
 
         lolunit_assert_equal(30, a[0].m1);
         lolunit_assert_equal(40, a[0].m2);