/*

* Integer Rounding Functions

* (C) 1999-2007 Jack Lloyd

*

* Botan is released under the Simplified BSD License (see license.txt)

*/

#ifndef BOTAN_ROUNDING_H_

#define BOTAN_ROUNDING_H_

#include <botan/assert.h>

#include <botan/types.h>

namespace Botan {

/**

* Integer rounding

*

* Returns an integer z such that n <= z <= n + align_to

* and z % align_to == 0

*

* @param n an integer

* @param align_to the alignment boundary

* @return n rounded up to a multiple of align_to

*/

constexpr inline size_t round_up(size_t n, size_t align_to) {

   // Arguably returning n in this case would also be sensible

   BOTAN_ARG_CHECK(align_to != 0, "align_to must not be 0");

   if(n % align_to > 0) {

      const size_t adj = align_to - (n % align_to);

      BOTAN_ARG_CHECK(n + adj >= n, "Integer overflow during rounding");

      n += adj;

   }

   return n;

}

}  // namespace Botan

#endif