Added thirdparty: boost library

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

@@ -0,0 +1,79 @@
+//  (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_MODF_HPP
+#define BOOST_MATH_CCMATH_MODF_HPP
+
+#include <boost/math/ccmath/detail/config.hpp>
+
+#ifdef BOOST_MATH_NO_CCMATH
+#error "The header <boost/math/modf.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>
+#include <boost/math/ccmath/trunc.hpp>
+
+namespace boost::math::ccmath {
+
+namespace detail {
+
+template <typename Real>
+inline constexpr Real modf_error_impl(Real x, Real* iptr)
+{
+    *iptr = x;
+    return boost::math::ccmath::abs(x) == Real(0) ? x :
+           x > Real(0) ? Real(0) : -Real(0);
+}
+
+template <typename Real>
+inline constexpr Real modf_nan_impl(Real x, Real* iptr)
+{
+    *iptr = x;
+    return x;
+}
+
+template <typename Real>
+inline constexpr Real modf_impl(Real x, Real* iptr)
+{
+    *iptr = boost::math::ccmath::trunc(x);
+    return (x - *iptr);
+}
+
+} // Namespace detail
+
+template <typename Real>
+inline constexpr Real modf(Real x, Real* iptr)
+{
+    if(BOOST_MATH_IS_CONSTANT_EVALUATED(x))
+    {
+        return boost::math::ccmath::abs(x) == Real(0) ? detail::modf_error_impl(x, iptr) :
+               boost::math::ccmath::isinf(x) ? detail::modf_error_impl(x, iptr) :
+               boost::math::ccmath::isnan(x) ? detail::modf_nan_impl(x, iptr) :
+               boost::math::ccmath::detail::modf_impl(x, iptr);
+    }
+    else
+    {
+        using std::modf;
+        return modf(x, iptr);
+    }
+}
+
+inline constexpr float modff(float x, float* iptr)
+{
+    return boost::math::ccmath::modf(x, iptr);
+}
+
+#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
+inline constexpr long double modfl(long double x, long double* iptr)
+{
+    return boost::math::ccmath::modf(x, iptr);
+}
+#endif
+
+} // Namespaces
+
+#endif // BOOST_MATH_CCMATH_MODF_HPP