constexpr isunordered (#745)

doc/sf/ccmath.qbk

@@ -179,6 +179,9 @@ All of the following functions require C++17 or greater.
         template <typename Arithmetic1, typename Arithmetic2 = Arithmetic1>
         inline constexpr bool islessequal(Arithmetic1 x, Arithmetic2 y) noexcept
 
+        template <typename T>
+        inline constexpr bool isunordered(T x, T y) noexcept
+
     } // Namespaces
 
 [endsect] [/section:ccmath Constexpr CMath]

include/boost/math/ccmath/ccmath.hpp

@@ -37,5 +37,6 @@
 #include <boost/math/ccmath/isgreaterequal.hpp>
 #include <boost/math/ccmath/isless.hpp>
 #include <boost/math/ccmath/islessequal.hpp>
+#include <boost/math/ccmath/isunordered.hpp>
 
 #endif // BOOST_MATH_CCMATH_HPP

include/boost/math/ccmath/isunordered.hpp

@@ -0,0 +1,31 @@
+//  (C) Copyright Matt Borland 2022.
+//  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_ISUNORDERED_HPP
+#define BOOST_MATH_CCMATH_ISUNORDERED_HPP
+
+#include <cmath>
+#include <boost/math/tools/is_constant_evaluated.hpp>
+#include <boost/math/ccmath/isnan.hpp>
+
+namespace boost::math::ccmath {
+
+template <typename T>
+inline constexpr bool isunordered(const T x, const T y) noexcept
+{
+    if(BOOST_MATH_IS_CONSTANT_EVALUATED(x))
+    {
+        return boost::math::ccmath::isnan(x) || boost::math::ccmath::isnan(y);
+    }
+    else
+    {
+        using std::isunordered;
+        return isunordered(x, y);
+    }
+}
+
+} // Namespaces
+
+#endif // BOOST_MATH_CCMATH_ISUNORDERED_HPP

test/Jamfile.v2

@@ -151,6 +151,7 @@ test-suite special_fun :
    [ run ccmath_isgreaterequal_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
    [ run ccmath_isless_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
    [ run ccmath_islessequal_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
+   [ run ccmath_isunordered_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
    [ run log1p_expm1_test.cpp test_instances//test_instances pch_light ../../test/build//boost_unit_test_framework  ]
    [ run powm1_sqrtp1m1_test.cpp test_instances//test_instances pch_light ../../test/build//boost_unit_test_framework  ]
    [ run git_issue_705.cpp ../../test/build//boost_unit_test_framework  ]

test/ccmath_isunordered_test.cpp

@@ -0,0 +1,50 @@
+//  (C) Copyright Matt Borland 2022.
+//  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)
+
+#include <cmath>
+#include <cfloat>
+#include <cstdint>
+#include <limits>
+#include <type_traits>
+#include <boost/math/ccmath/isunordered.hpp>
+
+#ifdef BOOST_HAS_FLOAT128
+#include <boost/multiprecision/float128.hpp>
+#endif
+
+template <typename T>
+constexpr void test()
+{
+    static_assert(boost::math::ccmath::isunordered(std::numeric_limits<T>::quiet_NaN(), T(0)));
+    static_assert(boost::math::ccmath::isunordered(T(0), std::numeric_limits<T>::quiet_NaN()));
+    static_assert(boost::math::ccmath::isunordered(std::numeric_limits<T>::quiet_NaN(), std::numeric_limits<T>::quiet_NaN()));
+
+    static_assert(!boost::math::ccmath::isunordered(T(0), std::numeric_limits<T>::infinity()));
+    static_assert(!boost::math::ccmath::isunordered(std::numeric_limits<T>::infinity(), T(0)));
+    static_assert(!boost::math::ccmath::isunordered(T(1), T(2)));
+}
+
+#if !defined(BOOST_MATH_NO_CONSTEXPR_DETECTION) && !defined(BOOST_MATH_USING_BUILTIN_CONSTANT_P)
+int main()
+{
+    test<float>();
+    test<double>();
+
+    #ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
+    test<long double>();
+    #endif
+    
+    #ifdef BOOST_HAS_FLOAT128
+    test<boost::multiprecision::float128>();
+    #endif
+
+    return 0;
+}
+#else
+int main()
+{
+    return 0;
+}
+#endif

test/compile_test/ccmath_isunordered_incl_test.cpp

@@ -0,0 +1,16 @@
+//  (C) Copyright Matt Borland 2022.
+//  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)
+
+#include <boost/math/ccmath/isunordered.hpp>
+#include "test_compile_result.hpp"
+
+void compile_and_link_test()
+{
+   check_result<float>(boost::math::ccmath::isunordered(1.0f, 1.0f));
+   check_result<double>(boost::math::ccmath::isunordered(1.0, 1.0));
+#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
+   check_result<long double>(boost::math::ccmath::isunordered(1.0l, 1.0l));
+#endif
+}