examples/manual/mask_array.cpp

/**************************************************************************
 *
 * mask_array.cpp -- Mask array examples
 *
 * $Id: //stdlib/dev/examples/stdlib/manual/mask_array.cpp#12 $
 *
 ***************************************************************************
 *
 * Copyright (c) 1994-2005 Quovadx,  Inc., acting through its  Rogue Wave
 * Software division. Licensed under the Apache License, Version 2.0 (the
 * "License");  you may  not use this file except  in compliance with the
 * License.    You    may   obtain   a   copy   of    the   License    at
 * http://www.apache.org/licenses/LICENSE-2.0.    Unless   required    by
 * applicable law  or agreed to  in writing,  software  distributed under
 * the License is distributed on an "AS IS" BASIS,  WITHOUT WARRANTIES OR
 * CONDITIONS OF  ANY KIND, either  express or implied.  See  the License
 * for the specific language governing permissions  and limitations under
 * the License.
 * 
 **************************************************************************/

#include <iostream>    // for cout, endl
#include <valarray.h>  // Includes valarray and provides stream inserter.
#include <examples.h>  // Generic header for all examples.

typedef std::valarray<int>    valarray_t;
typedef std::valarray<bool>   maskarray_t;

int main(void) {

  // Create a valarray of ints.
  valarray_t::value_type   ibuf[10] = {0,1,2,3,4,5,6,7,8,9};
  valarray_t               vi(ibuf, 10);

  // Create a valarray of bools for a mask.
  maskarray_t::value_type  mbuf[10] = {1,0,1,1,1,0,0,1,1,0};
  maskarray_t              mask(mbuf,10);

  // Print out the valarray<int>.
  std::cout << "original valarray<int> vi\n\n" << vi << "\n\n";

  // Print out the valarray<bool>.
  std::cout << "original valarray<bool> mask\n\n" << mask << "\n\n";

  // Print a mask array.
  std::cout << "vi[mask]\n\n" << vi[mask] << "\n\n";

  // Double the values of the masked array and print out.
  vi[mask] += static_cast<valarray_t> (vi[mask]);
  std::cout << "vi[mask] += vi[mask]\n\n" << vi << std::endl;

  return 0;
}