///////////////////////////////////////////////////////////////////////////////
//  Copyright Christopher Kormanyos 2023 - 2025.
//  Distributed under the Boost Software License, Version 1.0.
//  (See accompanying file LICENSE_1_0.txt or copy at
//  http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef BOOST_MP_CPP_DF_QF_DETAIL_CCMATH_SQRT_2023_01_07_HPP
#define BOOST_MP_CPP_DF_QF_DETAIL_CCMATH_SQRT_2023_01_07_HPP

#include <cmath>
#include <type_traits>

namespace boost { namespace multiprecision { namespace backends { namespace cpp_df_qf_detail { namespace ccmath {

namespace detail {

// LCOV_EXCL_START
template <typename Real>
constexpr auto sqrt_impl_2(Real x, Real s, Real s2) noexcept -> Real
{
   return ((!(s < s2)) ? s2 : sqrt_impl_2(x, (x / s + s) / 2, s));
}

template <typename Real>
constexpr auto sqrt_impl_1(Real x, Real s) noexcept -> Real
{
   return sqrt_impl_2(x, (x / s + s) / 2, s);
}

template <typename Real>
constexpr auto sqrt_impl(Real x) noexcept -> Real
{
   return sqrt_impl_1(x, x > 1 ? x : Real(1));
}
// LCOV_EXCL_STOP

} // namespace detail

template <typename Real>
constexpr auto sqrt(Real x) noexcept -> Real
{
   if (BOOST_MP_IS_CONST_EVALUATED(x))
   {
      return detail::sqrt_impl<Real>(x); // LCOV_EXCL_LINE
   }
   else
   {
      using std::sqrt;

      return sqrt(x);
   }
}

} } } } } // namespace boost::multiprecision::backends::cpp_df_qf_detail::ccmath

#endif // BOOST_MP_CPP_DF_QF_DETAIL_CCMATH_SQRT_2023_01_07_HPP