/usr/include/linbox/switch/boolean.h is in liblinbox-dev 1.3.2-1.1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 | /* linbox/switch/boolean.h
* Copyright (C) 1999-2001 William J Turner
*
* Written by William J Turner <wjturner@math.ncsu.edu>,
*
* -----------------------------------------------------------
* 2002-09-26 Bradford Hovinen <bghovinen@math.uwaterloo.ca>
*
* Refactoring: The switch object now contains only the information for one 2x2
* block. A vector of switches is maintained by the butterfly preconditioner
* instead of the switch object. Since there will be many switch objects, they
* should be kept very lightweight, so the field is not maintained in the object
* itself, but instead passed to apply and applyTranspose. Since those methods
* are inline, this does not create overhead. apply and applyTranspose now take
* four field elements: the source elements and destination elements. This
* eliminates the need to keep an additional temporary in the class, and
* eliminates the need for copying in the butterfly.
*
* -----------------------------------------------------------
* 2002-08-20 Bradford Hovinen <hovinen@cis.udel.edu>
*
* Brought this file into the current Linbox framework:
* - Renamed file as boolean.h
* - Renamed class boolean_switch as BooleanSwitch
* - Reindent
* -----------------------------------------------------------
*
*
* ========LICENCE========
* This file is part of the library LinBox.
*
* LinBox is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
* ========LICENCE========
*.
*/
#ifndef __LINBOX_boolean_H
#define __LINBOX_boolean_H
#include <vector>
namespace LinBox
{
class BooleanSwitchFactory;
/** Boolean switch object.
* This is a switch predicate object that is applied
* to two references to elements to switch them as needed
* by the \ref Butterfly\ Switching\ Network\ BlackBox\ Matrix\ Object.
*/
class BooleanSwitch {
public:
typedef BooleanSwitch Self_t;
typedef BooleanSwitchFactory Factory;
/** Constructor from an STL vector of booleans.
* The switch is applied using the vector of booleans.
* A true value means to swap the two elements, and a false
* value means not to.
* The apply function starts at the beginning of the vector moving
* forward through it, and applyTranspose function starts at the end
* moving backwards. Both repeat the vector after they pass through it.
* @param s vector of switches
*/
BooleanSwitch (const bool s) :
_s (s)
{}
/** Destructor.
*/
~BooleanSwitch () {}
/** Apply switch function.
* Switches the elements in references according to current boolean
* value. Swaps the elements if boolean is true, otherwise does nothing.
* It is templatized by the element type to be swapped.
* @return bool \c true if swapped, \c false otherwise
* @param F
* @param x reference to first element to be switched
* @param y reference to second element to be switched
*/
template <class Field>
bool apply (const Field &F,
typename Field::Element &x,
typename Field::Element &y) const;
/** Apply switch transpose function.
* Switches the elements in references according to current boolean
* value. Swaps the elements if boolean is true, otherwise does nothing.
* It is templatized by the element type to be swapped.
* @return bool \c true if swapped, \c false otherwise
* @param F
* @param x reference to first element to be switched
* @param y reference to second element to be switched
*/
template <class Field>
bool applyTranspose (const Field &F,
typename Field::Element &x,
typename Field::Element &y) const;
template<typename _Tp1>
struct rebind {
typedef BooleanSwitch other;
};
protected:
bool _s;
}; // class boolean_switch
/** Boolean switch factory
*
* This class facilitates construction of boolean switch objects by the
* butterfly matrix.
*/
class BooleanSwitchFactory {
public:
/** Constructor from an STL vector of bools
*/
BooleanSwitchFactory (const std::vector<bool> &switches) :
_switches (switches), _iter (switches.begin ())
{}
/** Construct and return a boolean switch object
*
* This function walks through the switches object given in the
* constructor, advancing on each invocation. It wraps around to the
* beginning of the vector when it reaches the end.
*/
BooleanSwitch makeSwitch ()
{
if (_iter == _switches.end ())
_iter = _switches.begin ();
return BooleanSwitch (*_iter++);
}
private:
const std::vector<bool> &_switches;
std::vector<bool>::const_iterator _iter;
};
template <class Field>
inline bool BooleanSwitch::apply (const Field &F,
typename Field::Element &x,
typename Field::Element &y) const
{
if (_s)
std::swap (x, y);
return _s;
}
template <class Field>
inline bool BooleanSwitch::applyTranspose (const Field &F,
typename Field::Element &x,
typename Field::Element &y) const
{
if (_s)
std::swap (x, y);
return _s;
}
}
#endif // __LINBOX_boolean_H
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