Operations.h

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/****************************************************************/
/* Parallel Combinatorial BLAS Library (for Graph Computations) */
/* version 1.6 -------------------------------------------------*/
/* date: 6/15/2017 ---------------------------------------------*/
/* authors: Ariful Azad, Aydin Buluc  --------------------------*/
/****************************************************************/
/*
 Copyright (c) 2010-2017, The Regents of the University of California
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 */


#ifndef _OPERATIONS_H_
#define _OPERATIONS_H_

#include <iostream>
#include <functional>
#include <cmath>
#include <limits>
#include "psort/MersenneTwister.h"

namespace combblas {

template<typename T1, typename T2>
struct equal_first
{
    bool operator()(std::pair<T1,T2> & lhs, std::pair<T1,T2> & rhs){
        return lhs.first == rhs.first;
    }
};



template<typename T>
struct myset: public std::unary_function<T, T>
{
  myset(T myvalue): value(myvalue) {};
  const T& operator()(const T& x) const
  {
    return value;
  } 
  T value;
};


template<typename T>
struct identity : public std::unary_function<T, T>
{
  const T operator()(const T& x) const
  {
    return x;
  }
};


// Because identify reports ambiguity in PGI compilers
template<typename T>
struct myidentity : public std::unary_function<T, T>
{
  const T operator()(const T& x) const
  {
    return x;
  }
};


template<typename T>
struct totality : public std::unary_function<T, bool>
{
  bool operator()(const T& x) const
  {
    return true;
  }
};
    
    
template<typename T>
struct safemultinv : public std::unary_function<T, T>
{
  const T operator()(const T& x) const
  {
    T inf = std::numeric_limits<T>::max();
        return (x == 0) ? inf:(1/x);
  }
};


template<typename T>
struct sel2nd: public std::binary_function<T, T, T>
{
    const T& operator()(const T& x, const T & y) const
    {
        return y;
    }
};

template<typename T1, typename T2>
struct bintotality : public std::binary_function<T1, T2, bool>
{
  bool operator()(const T1& x, const T2 & y) const
  {
        return true;
  }
};



struct exponentiate : public std::binary_function<double, double, double> 
{
    double operator()(double x, double y) const { return std::pow(x, y); }
};


template<typename T>
struct maximum : public std::binary_function<T, T, T>
{
  const T operator()(const T& x, const T& y) const
  {
    return x < y? y : x;
  }
};


template<typename T>
struct minimum : public std::binary_function<T, T, T>
{
  const T operator()(const T& x, const T& y) const
  {
    return x < y? x : y;
  }
};

template<typename T>
struct RandReduce : public std::binary_function<T, T, T>
{
    const T operator()(const T& x, const T& y) 
    {
        return (M.rand() < 0.5)? x : y;
    }
    RandReduce()
    {
    #ifdef DETERMINISTIC
        M = MTRand(1);
    #else
        M = MTRand();   // generate random numbers with Mersenne Twister
    #endif
    }
    MTRand M;
};

template<typename T>
struct SetIfNotEqual : public std::binary_function<T, T, T>
{
    const T operator()(const T& x, const T& y)
    {
        if(x != y)
        {
            return valuetoset;
        }
        else
        {
            return x;
        }
    }
    SetIfNotEqual(T value):valuetoset(value) { };
    T valuetoset;
};


template<typename T>
struct bitwise_and : public std::binary_function<T, T, T>
{
  T operator()(const T& x, const T& y) const
  {
    return x & y;
  }
};


template<typename T>
struct bitwise_or : public std::binary_function<T, T, T>
{
  T operator()(const T& x, const T& y) const
  {
    return x | y;
  }
};

template<typename T>
struct logical_xor : public std::binary_function<T, T, T>
{
  T operator()(const T& x, const T& y) const
  {
    return (x || y) && !(x && y);
  }
};

template<typename T>
struct bitwise_xor : public std::binary_function<T, T, T>
{
  T operator()(const T& x, const T& y) const
  {
    return x ^ y;
  }
};

}



#endif