rand.h

// -*- mode: c++; fill-column: 80; c-basic-offset: 2; indent-tabs-mode: nil -*-
/*
    Copyright (c) 2010 Juan Jose Garcia Ripoll

    Tensor is free software; you can redistribute it and/or modify it
    under the terms of the GNU Library General Public License as published
    by the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program 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 Library General Public License for more details.

    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#ifndef TENSOR_RAND_H
#define TENSOR_RAND_H

#include <tensor/numbers.h>

namespace tensor {

void rand_reseed();

template<class number> number rand() {
  return static_cast<number>(rand<double>());
}

template<> int rand<int>();
template<> unsigned int rand<unsigned int>();
template<> long rand<long>();
template<> unsigned long rand<unsigned long>();
template<> float rand<float>();
template<> double rand<double>();
template<> cdouble rand<cdouble>();

template<class real_number> inline real_number rand(real_number upper_limit) {
  return static_cast<real_number>(upper_limit * rand<double>());
}

template<class real_number> inline real_number rand(real_number lower_limit,
                                          real_number upper_limit) {
  return rand<real_number>(upper_limit - lower_limit) + lower_limit;
}

template<> inline int rand<int>(int upper) {
  if (upper)
    return rand<unsigned int>() % upper;
  return 0;
}

template<> inline int rand<int>(int lower, int upper) {
  return rand<int>(upper - lower) + lower;
}

template<> inline long rand<long>(long upper) {
  if (upper)
    return (long)rand<unsigned long>() % upper;
  return 0;
}

template<> inline long rand<long>(long lower, long upper) {
  return rand<long>(upper - lower) + lower;
}

template<> inline unsigned long rand<unsigned long>(unsigned long upper) {
  if (upper)
    return rand<unsigned long>() % upper;
  return 0;
}

template<> inline unsigned long rand<unsigned long>(unsigned long lower, unsigned long upper) {
  return rand<unsigned long>(upper - lower) + lower;
}
} // tensor

#endif // !TENSOR_RAND_H