Added thirdparty: boost library

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

@@ -0,0 +1,47 @@
+//  (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_ISNORMAL_HPP
+#define BOOST_MATH_ISNORMAL_HPP
+
+#include <boost/math/ccmath/detail/config.hpp>
+
+#ifdef BOOST_MATH_NO_CCMATH
+#error "The header <boost/math/isnormal.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 {
+
+template <typename T>
+inline constexpr bool isnormal(T x)
+{
+    if(BOOST_MATH_IS_CONSTANT_EVALUATED(x))
+    {   
+        return x == T(0) ? false :
+               boost::math::ccmath::isinf(x) ? false :
+               boost::math::ccmath::isnan(x) ? false :
+               boost::math::ccmath::abs(x) < (std::numeric_limits<T>::min)() ? false : true;
+    }
+    else
+    {
+        using std::isnormal;
+
+        if constexpr (!std::is_integral_v<T>)
+        {
+            return isnormal(x);
+        }
+        else
+        {
+            return isnormal(static_cast<double>(x));
+        }
+    }
+}
+}
+
+#endif // BOOST_MATH_ISNORMAL_HPP