Added thirdparty: boost library

thirdparty/include/boost/math/ccmath/floor.hpp

@@ -0,0 +1,123 @@
+//  (C) Copyright Matt Borland 2021.
+//  Use, modification and distribution are subject to 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_MATH_CCMATH_FLOOR_HPP
+#define BOOST_MATH_CCMATH_FLOOR_HPP
+
+#include <boost/math/ccmath/detail/config.hpp>
+
+#ifdef BOOST_MATH_NO_CCMATH
+#error "The header <boost/math/floor.hpp> can only be used in C++17 and later."
+#endif
+
+#include <boost/math/ccmath/abs.hpp>
+#include <boost/math/ccmath/isinf.hpp>
+#include <boost/math/ccmath/isnan.hpp>
+
+namespace boost::math::ccmath {
+
+namespace detail {
+
+template <typename T>
+inline constexpr T floor_pos_impl(T arg) noexcept
+{
+    T result = 1;
+
+    if(result < arg)
+    {
+        while(result < arg)
+        {
+            result *= 2;
+        }
+        while(result > arg)
+        {
+            --result;
+        }
+
+        return result;
+    }
+    else
+    {
+        return T(0);
+    }
+}
+
+template <typename T>
+inline constexpr T floor_neg_impl(T arg) noexcept
+{
+    T result = -1;
+
+    if(result > arg)
+    {
+        while(result > arg)
+        {
+            result *= 2;
+        }
+        while(result < arg)
+        {
+            ++result;
+        }
+        if(result != arg)
+        {
+            --result;
+        }
+    }
+
+    return result;
+}
+
+template <typename T>
+inline constexpr T floor_impl(T arg) noexcept
+{
+    if(arg > 0)
+    {
+        return floor_pos_impl(arg);
+    }
+    else
+    {
+        return floor_neg_impl(arg);
+    }
+}
+
+} // Namespace detail
+
+template <typename Real, std::enable_if_t<!std::is_integral_v<Real>, bool> = true>
+inline constexpr Real floor(Real arg) noexcept
+{
+    if(BOOST_MATH_IS_CONSTANT_EVALUATED(arg))
+    {
+        return boost::math::ccmath::abs(arg) == Real(0) ? arg :
+               boost::math::ccmath::isinf(arg) ? arg :
+               boost::math::ccmath::isnan(arg) ? arg :
+               boost::math::ccmath::detail::floor_impl(arg);
+    }
+    else
+    {
+        using std::floor;
+        return floor(arg);
+    }
+}
+
+template <typename Z, std::enable_if_t<std::is_integral_v<Z>, bool> = true>
+inline constexpr double floor(Z arg) noexcept
+{
+    return boost::math::ccmath::floor(static_cast<double>(arg));
+}
+
+inline constexpr float floorf(float arg) noexcept
+{
+    return boost::math::ccmath::floor(arg);
+}
+
+#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
+inline constexpr long double floorl(long double arg) noexcept
+{
+    return boost::math::ccmath::floor(arg);
+}
+#endif
+
+} // Namespaces
+
+#endif // BOOST_MATH_CCMATH_FLOOR_HPP