Adding upstream version 4:24.2.0.upstream/4%24.2.0

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

1 files changed, 157 insertions, 0 deletions

diff --git a/include/o3tl/enumarray.hxx b/include/o3tl/enumarray.hxx
new file mode 100644
index 0000000000..4fd5cab315
--- /dev/null
+++ b/include/o3tl/enumarray.hxx
@@ -0,0 +1,157 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#ifndef INCLUDED_O3TL_ENUMARRAY_HXX
+#define INCLUDED_O3TL_ENUMARRAY_HXX
+
+#include <iterator>
+#include <type_traits>
+#include <utility>
+#include <array>
+#include <cassert>
+
+namespace o3tl {
+
+template<typename EA>
+class enumarray_iterator;
+template<typename EA>
+class enumarray_const_iterator;
+
+///
+/// This is a container convenience class for arrays indexed by enum values.
+///
+/// This assumes that the 'enum class' definition
+///  - starts at zero
+///  - has no holes in its sequence of values
+///  - defines a value called LAST which refers to the greatest constant.
+///
+/// \param E the 'enum class' type.
+/// \param V the value type to be stored in the array
+template<typename E, typename V>
+class enumarray final
+{
+public:
+    typedef enumarray<E, V> self_type;
+    typedef enumarray_iterator<self_type> iterator;
+    typedef enumarray_const_iterator<self_type> const_iterator;
+
+    typedef V             value_type;
+    typedef E             key_type;
+    typedef size_t        size_type;
+
+    static const size_type max_index = static_cast<size_type>(E::LAST);
+
+    // If this ctor only had the args parameter pack, it would erroneously get picked as a better
+    // choice than the (implicit) copy ctor (taking a const lvalue reference) when a copy is made
+    // from a non-const lvalue enumarray; the easiest way to avoid that is the additional arg
+    // parameter; and to keep things simple that parameter is always passed by const lvalue
+    // reference for now even if there could be cases where passing it by rvalue reference might be
+    // beneficial or even necessary if V is a move-only type:
+    template<typename... T> constexpr enumarray(V const & arg, T && ...args):
+        detail_values{arg, std::forward<T>(args)...}
+    {
+        static_assert(sizeof... (T) == max_index);
+    }
+
+    // coverity[uninit_ctor] - by design:
+    enumarray() {}
+
+    const V& operator[](E index) const
+    {
+        assert(index>=static_cast<E>(0) && index<=E::LAST);
+        return detail_values[static_cast<size_type>(index)];
+    }
+
+    V& operator[](E index)
+    {
+        assert(index>=static_cast<E>(0) && index<=E::LAST);
+        return detail_values[static_cast<size_type>(index)];
+    }
+
+    void fill(V val)
+    { for (size_type i=0; i<=max_index; ++i) detail_values[i] = val; }
+
+    static size_type size()        { return max_index + 1; }
+    iterator         begin()       { return iterator(*this, 0); }
+    iterator         end()         { return iterator(*this, size()); }
+    const_iterator   begin() const { return const_iterator(*this, 0); }
+    const_iterator   end() const   { return const_iterator(*this, size()); }
+
+    V*               data()       { return detail_values.data(); }
+
+private:
+    std::array<V, max_index + 1> detail_values;
+};
+
+
+template<typename EA>
+class enumarray_iterator {
+    EA*         m_buf;
+    size_t      m_pos;
+public:
+    typedef enumarray_iterator<EA>  self_type;
+    typedef typename EA::value_type value_type;
+    typedef typename EA::key_type   key_type;
+    typedef std::bidirectional_iterator_tag iterator_category; //should be random access, but that would require define subtraction operators on the enums
+    typedef
+        typename std::make_signed<
+            typename std::underlying_type<typename EA::key_type>::type>::type
+        difference_type;
+    typedef typename EA::value_type*   pointer;
+    typedef typename EA::value_type&   reference;
+
+    enumarray_iterator(EA& b, size_t start_pos)
+         : m_buf(&b), m_pos(start_pos) {}
+    value_type& operator*()  const { return (*m_buf)[static_cast<key_type>(m_pos)]; }
+    value_type* operator->() const { return &(operator*()); }
+    self_type&  operator++() { ++m_pos; return *this; }
+    bool        operator!=(self_type const & other) const { return m_buf != other.m_buf || m_pos != other.m_pos; }
+    bool        operator==(self_type const & other) const { return m_buf == other.m_buf && m_pos == other.m_pos; }
+};
+
+template<typename EA>
+class enumarray_const_iterator {
+    EA const *  m_buf;
+    size_t      m_pos;
+public:
+    typedef enumarray_const_iterator<EA>    self_type;
+    typedef typename EA::value_type const   value_type;
+    typedef typename EA::key_type           key_type;
+    typedef std::bidirectional_iterator_tag iterator_category; //should be random access, but that would require define subtraction operators on the enums
+    typedef
+        typename std::make_signed<
+            typename std::underlying_type<typename EA::key_type>::type>::type
+                                            difference_type;
+    typedef typename EA::value_type const * pointer;
+    typedef typename EA::value_type const & reference;
+
+    enumarray_const_iterator(EA const & b, size_t start_pos)
+         : m_buf(&b), m_pos(start_pos) {}
+    value_type& operator*()  const { return (*m_buf)[static_cast<key_type>(m_pos)]; }
+    value_type* operator->() const { return &(operator*()); }
+    self_type&  operator++() { ++m_pos; return *this; }
+    bool        operator!=(self_type const & other) const { return m_buf != other.m_buf || m_pos != other.m_pos; }
+    bool        operator==(self_type const & other) const { return m_buf == other.m_buf && m_pos == other.m_pos; }
+};
+
+}; // namespace o3tl
+
+#endif /* INCLUDED_O3TL_ENUMARRAY_HXX */
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */