src/base/mod_num.hh

   1 /*
   2  * Copyright (c) 2002-2005 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Authors: Steve Raasch
  29  */
  30
  31 template<class T, T MV>
  32 class ModNum {
  33   private:
  34     T value;
  35
  36     //  Compiler should optimize this
  37     void setValue(T n) { value = n % MV; }
  38
  39   public:
  40     ModNum() {}
  41     ModNum(T n) { setValue(n); }
  42     ModNum(const ModNum<T, MV> &n) : value(n.value) {}
  43
  44     ModNum operator=(T n) {
  45         setValue(n);
  46         return *this;
  47     }
  48
  49     const ModNum operator=(ModNum n) {
  50         value = n.value;
  51         return *this;
  52     }
  53
  54     //  Return the value if object used as RHS
  55     operator T() const { return value; }
  56
  57     //
  58     //  Operator "+="
  59     //
  60     const ModNum<T, MV> operator+=(ModNum<T, MV> r) {
  61         setValue(value + r.value);
  62         return *this;
  63     }
  64
  65     const ModNum<T, MV> operator+=(T r) {
  66         setValue(value + r);
  67         return *this;
  68     }
  69
  70     //
  71     //  Operator "-="
  72     //
  73     const ModNum<T, MV> operator-=(ModNum<T, MV> r) {
  74         setValue(value - r.value);
  75         return *this;
  76     }
  77
  78     const ModNum<T, MV> operator-=(T r) {
  79         setValue(value - r);
  80         return *this;
  81     }
  82
  83     //
  84     //  Operator "++"
  85     //
  86     //  PREFIX (like ++a)
  87     const ModNum<T, MV> operator++() {
  88         *this += 1;
  89         return *this;
  90     }
  91
  92     //  POSTFIX (like a++)
  93     const ModNum<T, MV> operator++(int) {
  94         ModNum<T, MV> rv = *this;
  95
  96         *this += 1;
  97
  98         return rv;
  99     }
 100
 101     //
 102     //  Operator "--"
 103     //
 104     //  PREFIX (like --a)
 105     const ModNum<T, MV> operator--() {
 106         *this -= 1;
 107         return *this;
 108     }
 109
 110     //  POSTFIX (like a--)
 111     const ModNum<T, MV> operator--(int) {
 112         ModNum<T, MV> rv = *this;
 113         *this -= 1;
 114         return rv;
 115     }
 116 };
 117
 118
 119 //
 120 //  Define operator "+" like this to avoid creating a temporary
 121 //
 122 template<class T, T MV>
 123 inline ModNum<T, MV>
 124 operator+(ModNum<T, MV> l, ModNum<T, MV> r) {
 125     l += r;
 126     return l;
 127 }
 128
 129 template<class T, T MV>
 130 inline ModNum<T, MV>
 131 operator+(ModNum<T, MV> l, T r) {
 132     l += r;
 133     return l;
 134 }
 135
 136 template<class T, T MV>
 137 inline ModNum<T, MV>
 138 operator+(T l, ModNum<T, MV> r) {
 139     r += l;
 140     return r;
 141 }
 142
 143
 144 //
 145 //  Define operator "-" like this to avoid creating a temporary
 146 //
 147 template<class T, T MV>
 148 inline ModNum<T, MV>
 149 operator-(ModNum<T, MV> l, ModNum<T, MV> r) {
 150     l -= r;
 151     return l;
 152 }
 153
 154 template<class T, T MV>
 155 inline ModNum<T, MV>
 156 operator-(ModNum<T, MV> l, T r) {
 157     l -= r;
 158     return l;
 159 }
 160
 161 template<class T, T MV>
 162 inline ModNum<T, MV>
 163 operator-(T l, ModNum<T, MV> r) {
 164     r -= l;
 165     return r;
 166 }
 167
 168
 169 //
 170 //  Comparison operators
 171 //  (all other cases are handled with conversons)
 172 //
 173 template<class T, T MV>
 174 inline bool
 175 operator<(ModNum<T, MV> l, ModNum<T, MV> r) {
 176     return l.value < r.value;
 177 }
 178
 179 template<class T, T MV>
 180 inline bool
 181 operator>(ModNum<T, MV> l, ModNum<T, MV> r) {
 182     return l.value > r.value;
 183 }
 184
 185 template<class T, T MV>
 186 inline bool
 187 operator==(ModNum<T, MV> l, ModNum<T, MV> r) {
 188     return l.value == r.value;
 189 }
 190
 191 template<class T, T MV>
 192 inline bool
 193 operator<=(ModNum<T, MV> l, ModNum<T, MV> r) {
 194     return l.value <= r.value;
 195 }
 196
 197 template<class T, T MV>
 198 inline bool
 199 operator>=(ModNum<T, MV> l, ModNum<T, MV> r) {
 200     return l.value >= r.value;
 201 }
 202
 203