robot/include/rttr/detail/variant/variant_compare.cpp

/************************************************************************************
*                                                                                   *
*   Copyright (c) 2014 - 2018 Axel Menzel <info@rttr.org>                           *
*                                                                                   *
*   This file is part of RTTR (Run Time Type Reflection)                            *
*   License: MIT License                                                            *
*                                                                                   *
*   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     *
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*   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE   *
*   SOFTWARE.                                                                       *
*                                                                                   *
*************************************************************************************/

#include "rttr/detail/variant/variant_compare.h"
#include "rttr/type.h"
#include "rttr/variant.h"

#include <cmath>
#include <algorithm>

namespace rttr
{
namespace detail
{

/////////////////////////////////////////////////////////////////////////////////////////

static RTTR_INLINE bool is_floating_point(const type& type)
{
    return (type == type::get<float>() || type == type::get<double>());
}

/////////////////////////////////////////////////////////////////////////////////////////

static RTTR_INLINE bool almost_equal(double p1, double p2)
{
    return (std::abs(p1 - p2) * 1000000000000. <= std::min(std::abs(p1), std::abs(p2)));
}

/////////////////////////////////////////////////////////////////////////////////////////

bool variant_compare_equal(const variant& lhs, const type& lhs_type, const variant& rhs, const type& rhs_type, bool& ok)
{
    ok = true;
    if (is_floating_point(lhs_type) || is_floating_point(rhs_type))
    {
        return almost_equal(lhs.to_double(), rhs.to_double());
    }
    else
    {
        return (lhs.to_int64() == rhs.to_int64());
    }
}

/////////////////////////////////////////////////////////////////////////////////////////

bool variant_compare_less(const variant& lhs, const type& lhs_type, const variant& rhs, const type& rhs_type, bool& ok)
{
    ok = true;
    if (lhs_type.is_arithmetic() && rhs_type.is_arithmetic())
    {
        if (is_floating_point(lhs_type) || is_floating_point(rhs_type))
            return (lhs.to_double() < rhs.to_double());
        else
            return (lhs.to_int64() < rhs.to_int64());
    }
    else
    {
        variant lhs_tmp;
        if (lhs.convert(rhs_type, lhs_tmp))
            return lhs_tmp.compare_less(rhs, ok);

        if (!lhs.is_nullptr() && rhs.is_nullptr())
            return false;

        // as last try, do a string conversion
        bool ok1 = false;
        bool ok2 = false;
        auto ret = (lhs.to_string(&ok1) < rhs.to_string(&ok2));
        if (ok1 && ok2)
        {
            return ret;
        }
        else
        {
            ok = false;
            return false;
        }
    }
}

/////////////////////////////////////////////////////////////////////////////////////////

} // end namespace detail
} // end namespace rttr