include/o3tl/strong_int.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
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   5  * This Source Code Form is subject to the terms of the Mozilla Public
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   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #ifndef INCLUDED_O3TL_STRONG_INT_HXX
  21 #define INCLUDED_O3TL_STRONG_INT_HXX
  22
  23 #include <sal/config.h>
  24 #include <limits>
  25 #include <cassert>
  26 #include <type_traits>
  27 #include <compare>
  28 #include <config_options.h>
  29
  30 namespace o3tl
  31 {
  32
  33 #if !defined __COVERITY__
  34
  35 namespace detail {
  36
  37 template<typename T1, typename T2> constexpr
  38 typename std::enable_if<
  39     std::is_signed<T1>::value && std::is_signed<T2>::value, bool>::type
  40 isInRange(T2 value) {
  41     return value >= std::numeric_limits<T1>::min()
  42         && value <= std::numeric_limits<T1>::max();
  43 }
  44
  45 template<typename T1, typename T2> constexpr
  46 typename std::enable_if<
  47     std::is_signed<T1>::value && std::is_unsigned<T2>::value, bool>::type
  48 isInRange(T2 value) {
  49     return value
  50         <= static_cast<typename std::make_unsigned<T1>::type>(
  51             std::numeric_limits<T1>::max());
  52 }
  53
  54 template<typename T1, typename T2> constexpr
  55 typename std::enable_if<
  56     std::is_unsigned<T1>::value && std::is_signed<T2>::value, bool>::type
  57 isInRange(T2 value) {
  58     return value >= 0
  59         && (static_cast<typename std::make_unsigned<T2>::type>(value)
  60             <= std::numeric_limits<T1>::max());
  61 }
  62
  63 template<typename T1, typename T2> constexpr
  64 typename std::enable_if<
  65     std::is_unsigned<T1>::value && std::is_unsigned<T2>::value, bool>::type
  66 isInRange(T2 value) {
  67     return value <= std::numeric_limits<T1>::max();
  68 }
  69
  70 }
  71
  72 #endif
  73
  74 ///
  75 /// Wrap up an integer type so that we prevent accidental conversion to other integer types.
  76 ///
  77 /// e.g.
  78 ///   typedef o3tl::strong_int<unsigned, struct MyIntTag> MyInt;
  79 ///
  80 /// \param UNDERLYING_TYPE the underlying scalar type
  81 /// \param PHANTOM_TYPE    a type tag, used to distinguish this instantiation of the template
  82 ///                        from other instantiations with the same UNDERLYING_TYPE.
  83 ///
  84 template <typename UNDERLYING_TYPE, typename PHANTOM_TYPE>
  85 struct strong_int
  86 {
  87 public:
  88 // when compiling LO on macOS, debug builds will display a linking error where, see
  89 // <https://lists.freedesktop.org/archives/libreoffice/2024-February/091564.html>, "Our Clang
  90 // --enable-pch setup is known broken":
  91 #if defined MACOSX && defined __clang__ && __clang_major__ == 16 && ENABLE_PCH
  92     explicit constexpr strong_int(unsigned long long value) : m_value(value) {}
  93     explicit constexpr strong_int(unsigned long value) : m_value(value) {}
  94     explicit constexpr strong_int(long value) : m_value(value) {}
  95     explicit constexpr strong_int(int value) : m_value(value) {}
  96     explicit constexpr strong_int(unsigned int value) : m_value(value) {}
  97 #else
  98     template<typename T> explicit constexpr strong_int(
  99         T value,
 100         typename std::enable_if<std::is_integral<T>::value, int>::type = 0):
 101         m_value(value)
 102     {
 103 #if !defined __COVERITY__
 104         // catch attempts to pass in out-of-range values early
 105         assert(detail::isInRange<UNDERLYING_TYPE>(value)
 106                && "out of range");
 107 #endif
 108     }
 109 #endif
 110     strong_int() : m_value(0) {}
 111
 112     explicit constexpr operator UNDERLYING_TYPE() const { return m_value; }
 113     explicit operator bool() const { return m_value != 0; }
 114     UNDERLYING_TYPE get() const { return m_value; }
 115
 116     auto operator<=>(strong_int const & other) const = default;
 117
 118     strong_int& operator++() { ++m_value; return *this; }
 119     strong_int operator++(int) { UNDERLYING_TYPE nOldValue = m_value; ++m_value; return strong_int(nOldValue); }
 120     strong_int& operator--() { --m_value; return *this; }
 121     strong_int operator--(int) { UNDERLYING_TYPE nOldValue = m_value; --m_value; return strong_int(nOldValue); }
 122     strong_int& operator+=(strong_int const & other) { m_value += other.m_value; return *this; }
 123     strong_int& operator-=(strong_int const & other) { m_value -= other.m_value; return *this; }
 124     strong_int& operator%=(strong_int const & other) { m_value %= other.m_value; return *this; }
 125     strong_int& operator*=(strong_int const & other) { m_value *= other.m_value; return *this; }
 126     strong_int& operator/=(strong_int const & other) { m_value /= other.m_value; return *this; }
 127     [[nodiscard]]
 128     strong_int operator%(strong_int const & other) const { return strong_int(m_value % other.m_value); }
 129     [[nodiscard]]
 130     strong_int operator-() const { return strong_int(-m_value); }
 131     [[nodiscard]]
 132     strong_int operator*(strong_int const & other) const { return strong_int(m_value * other.m_value); }
 133     [[nodiscard]]
 134     strong_int operator/(strong_int const & other) const { return strong_int(m_value / other.m_value); }
 135
 136     bool anyOf(strong_int v) const {
 137       return *this == v;
 138     }
 139
 140     template<typename... Args>
 141     bool anyOf(strong_int first, Args... args) const {
 142       return *this == first || anyOf(args...);
 143     }
 144
 145 private:
 146     UNDERLYING_TYPE m_value;
 147 };
 148
 149 template <typename UT, typename PT>
 150 strong_int<UT,PT> operator+(strong_int<UT,PT> const & lhs, strong_int<UT,PT> const & rhs)
 151 {
 152     return strong_int<UT,PT>(lhs.get() + rhs.get());
 153 }
 154
 155 template <typename UT, typename PT>
 156 strong_int<UT,PT> operator-(strong_int<UT,PT> const & lhs, strong_int<UT,PT> const & rhs)
 157 {
 158     return strong_int<UT,PT>(lhs.get() - rhs.get());
 159 }
 160
 161 }; // namespace o3tl
 162
 163 #endif /* INCLUDED_O3TL_STRONG_INT_HXX */
 164
 165 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */