rounding.h

// Description: Rounding
// Documentation: math_functions.txt

#ifndef PASTELSYS_ROUNDING_H
#define PASTELSYS_ROUNDING_H

#include "pastel/sys/mytypes.h"
#include "pastel/sys/integer/integer_concept.h"

#include <type_traits>

namespace Pastel
{

    //! Rounds up 'that' to the next multiple of 'to'.
    /*!
   Preconditions:
   !negative(to)

   Time complexity: O(1)
   Exception safety: nothrow
   */
    template <Integer_Concept Integer>
    Integer roundUpTo(
        const Integer& that, const Integer& to);

    //! Rounds up to the next odd number.
    /*!
   Time complexity: O(1)
   Exception safety: nothrow
   */
    template <Integer_Concept Integer>
    Integer roundUpToOdd(const Integer& that);

    //! Rounds up to the next odd number.
    /*!
   Preconditions:
   Real is a native floating point type.

   Time complexity: O(1)
   Exception safety: nothrow
   */
    template <std::floating_point Real>
    integer roundUpToOdd(const Real& that);

    //! Rounds up to the next even number.
    /*!
   Time complexity: O(1)
   Exception safety: nothrow
   */
    template <Integer_Concept Integer>
    Integer roundUpToEven(const Integer& that);

    //! Rounds up to the next even number.
    /*!
   Preconditions:
   Real is a native floating point type.

   Time complexity: O(1)
   Exception safety: nothrow
   */
    template <std::floating_point Real>
    integer roundUpToEven(const Real& that);

    //! Rounds up to the next power of 2 (unsigned integers).
    /*!
   Preconditions:
   Integer is an unsigned native integer.

   Time complexity: O(log(SizeInBits<Integer>::value) + 1)
   Exception safety: nothrow
   */
    template <std::unsigned_integral Integer>
    Integer roundUpToPowerOfTwo(const Integer& that);

    //! Rounds up to the next power of 2 (signed integers).
    /*!
   Preconditions:
   Integer is a signed native integer.
   The next power of 2 can be represented.

   Time complexity: O(log(SizeInBits<Integer>::value) + 1)
   Exception safety: nothrow
   */
    template <std::signed_integral Integer>
    Integer roundUpToPowerOfTwo(const Integer& that);

    //! Rounds up 'that' to the next multiple of power of 2.
    /*!
   Preconditions:
   !negative(power)

   Time complexity: O(1)
   Exception safety: nothrow
   */
    template <Integer_Concept Integer>
    Integer roundUpToPowerOfTwo(
        const Integer& that, 
        integer power);

}

#include "pastel/sys/math/rounding.hpp"

#endif