Adding upstream version 7.0.6-dfsg.upstream/7.0.6-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 164 insertions, 0 deletions

diff --git a/include/iprt/nocrt/algorithm b/include/iprt/nocrt/algorithm
new file mode 100644
index 00000000..bf6102f8
--- /dev/null
+++ b/include/iprt/nocrt/algorithm
@@ -0,0 +1,164 @@
+/** @file
+ * IPRT / No-CRT - Minimal C++ algorithm header.
+ */
+
+/*
+ * Copyright (C) 2022 Oracle and/or its affiliates.
+ *
+ * This file is part of VirtualBox base platform packages, as
+ * available from https://www.virtualbox.org.
+ *
+ * This program 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, in version 3 of the
+ * License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses>.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
+ * in the VirtualBox distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
+ */
+
+#ifndef VBOX_INCLUDED_SRC_nocrt_algorithm
+#define VBOX_INCLUDED_SRC_nocrt_algorithm
+#ifndef RT_WITHOUT_PRAGMA_ONCE
+# pragma once
+#endif
+
+#ifdef _MSC_VER
+# pragma warning(push)
+# pragma warning(disable: 4643) /* warning C4643: Forward declaring 'ios_base' in namespace std is not permitted by the C++ Standard */
+#endif
+
+namespace std
+{
+    /**
+     * Swap the values pointed to by the two references.
+     */
+    template<typename a_Type>
+    void swap(a_Type &a_rObj1, a_Type &a_rObj2)
+    {
+        a_Type Tmp(a_rObj1);
+        a_rObj1 = a_rObj2;
+        a_rObj2 = Tmp;
+    }
+
+    /**
+     * Swap the values pointed to by two forward iterators.
+     */
+    template<typename a_ForwardIt1, typename a_ForwardIt2>
+    void iter_swap(a_ForwardIt1 a_It1, a_ForwardIt2 a_It2)
+    {
+        swap(*a_It1, *a_It2);
+    }
+
+    template<typename a_RandomIt>
+    void sort(a_RandomIt a_ItBegin, a_RandomIt a_ItEnd)
+    {
+        /* Note! Using shell sort here because it's tiny and we've got code for it. */
+        /** @todo replace with faster code.   */
+
+        /* Anything worth sorting? */
+        std::size_t const cElements = a_ItEnd - a_ItBegin;
+        if (cElements >= 1)
+        {
+            /* Loop on decreasing gap, ending with 1: */
+            std::size_t cGap = (cElements + 1) / 2;
+            while (cGap > 0)
+            {
+                /* Iterate from cGap till the end: */
+                for (std::size_t i = cGap; i < cElements; i++)
+                {
+                    /* Find the best suitable location for the item at 'i' comparing
+                       backwards in steps of 'cGap', swapping the item at 'i' with the
+                       one at '-cGap*j' if it's smaller, stopping if it's larger.
+
+                       Note! Original algorithm would make a copy of the item, this version
+                             avoids extra copies of sorted items at the cost of extra copies
+                             when dealing with unsorted ones a small cGaps values. */
+                    a_RandomIt ItCur = a_ItBegin + i;
+                    size_t     j     = i;
+                    do
+                    {
+                        j -= cGap;
+                        a_RandomIt ItAtGap = a_ItBegin + j;
+                        if (*ItAtGap < *ItCur)
+                            break;
+                        std::iter_swap(ItAtGap, ItCur);
+                        ItCur = ItAtGap;
+                    } while (j >= cGap);
+                }
+
+                /* This does not generate the most optimal gap sequence, but it has the
+                   advantage of being simple and avoid floating point. */
+                cGap /= 2;
+            }
+        }
+    }
+
+    template<typename a_RandomIt, typename a_FnCompareType>
+    void sort(a_RandomIt a_ItBegin, a_RandomIt a_ItEnd, a_FnCompareType a_fnComp)
+    {
+        /* Note! Using shell sort here because it's tiny and we've got code for it. */
+        /** @todo replace with faster code.   */
+
+        /* Anything worth sorting? */
+        std::size_t const cElements = a_ItEnd - a_ItBegin;
+        if (cElements >= 1)
+        {
+            /* Loop on decreasing gap, ending with 1: */
+            std::size_t cGap = (cElements + 1) / 2;
+            while (cGap > 0)
+            {
+                /* Iterate from cGap till the end: */
+                for (std::size_t i = cGap; i < cElements; i++)
+                {
+                    /* Find the best suitable location for the item at 'i' comparing
+                       backwards in steps of 'cGap', swapping the item at 'i' with the
+                       one at '-cGap*j' if it's smaller, stopping if it's larger.
+
+                       Note! Original algorithm would make a copy of the item, this version
+                             avoids extra copies of sorted items at the cost of extra copies
+                             when dealing with unsorted ones a small cGaps values. */
+                    a_RandomIt ItCur = a_ItBegin + i;
+                    size_t     j     = i;
+                    do
+                    {
+                        j -= cGap;
+                        a_RandomIt ItAtGap = a_ItBegin + j;
+                        if (a_fnComp(*ItAtGap, *ItCur))
+                            break;
+                        std::iter_swap(ItAtGap, ItCur);
+                        ItCur = ItAtGap;
+                    } while (j >= cGap);
+                }
+
+                /* This does not generate the most optimal gap sequence, but it has the
+                   advantage of being simple and avoid floating point. */
+                cGap /= 2;
+            }
+        }
+    }
+
+}
+
+#ifdef _MSC_VER
+# pragma warning(pop)
+#endif
+
+#endif /* !VBOX_INCLUDED_SRC_nocrt_algorithm */
+