Constexpr isfinite and isnormal (#674)

doc/sf/ccmath.qbk

@@ -42,6 +42,12 @@ All of the following functions require C++17 or greater.
         template <typename T>
         inline constexpr T fabs(T x);
 
+        template <typename T>
+        inline constexpr bool isfinite(T x);
+
+        template <typename T>
+        inline constexpr bool isnormal(T x);
+
     } // Namespaces
 
 [endsect] [/section:ccmath Constexpr CMath]

include/boost/math/ccmath/ccmath.hpp

@@ -12,5 +12,7 @@
 #include <boost/math/ccmath/isnan.hpp>
 #include <boost/math/ccmath/abs.hpp>
 #include <boost/math/ccmath/fabs.hpp>
+#include <boost/math/ccmath/isfinite.hpp>
+#include <boost/math/ccmath/isnormal.hpp>
 
 #endif // BOOST_MATH_CCMATH

include/boost/math/ccmath/isfinite.hpp

@@ -0,0 +1,50 @@
+//  (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_ISFINITE
+#define BOOST_MATH_CCMATH_ISFINITE
+
+#include <cmath>
+#include <type_traits>
+#include <boost/math/tools/is_constant_evaluated.hpp>
+#include <boost/math/ccmath/isinf.hpp>
+#include <boost/math/ccmath/isnan.hpp>
+
+namespace boost::math::ccmath {
+
+template <typename T>
+inline constexpr bool isfinite(T x)
+{
+    if(BOOST_MATH_IS_CONSTANT_EVALUATED(x))
+    {
+        // bool isfinite (IntegralType arg) is a set of overloads accepting the arg argument of any integral type
+        // equivalent to casting the integral argument arg to double (e.g. static_cast<double>(arg))
+        if constexpr (std::is_integral_v<T>)
+        {
+            return !boost::math::ccmath::isinf(static_cast<double>(x)) && !boost::math::ccmath::isnan(static_cast<double>(x));
+        }
+        else
+        {
+            return !boost::math::ccmath::isinf(x) && !boost::math::ccmath::isnan(x);
+        }
+    }
+    else
+    {
+        using std::isfinite;
+
+        if constexpr (!std::is_integral_v<T>)
+        {
+            return isfinite(x);
+        }
+        else
+        {
+            return isfinite(static_cast<double>(x));
+        }
+    }
+}
+
+}
+
+#endif // BOOST_MATH_CCMATH_ISFINITE

include/boost/math/ccmath/isnormal.hpp

@@ -0,0 +1,45 @@
+//  (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 <cmath>
+#include <limits>
+#include <type_traits>
+#include <boost/math/tools/is_constant_evaluated.hpp>
+#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

test/Jamfile.v2

@@ -125,6 +125,8 @@ test-suite special_fun :
    [ run ccmath_isinf_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
    [ run ccmath_isnan_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
    [ run ccmath_abs_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
+   [ run ccmath_isfinite_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ]
+   [ run ccmath_isnormal_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 special_functions_test.cpp ../../test/build//boost_unit_test_framework  ]

test/ccmath_isfinite_test.cpp

@@ -0,0 +1,68 @@
+//  (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)
+
+#include <cmath>
+#include <cfloat>
+#include <cstdint>
+#include <limits>
+#include <type_traits>
+#include <boost/math/ccmath/isfinite.hpp>
+
+#ifdef BOOST_HAS_FLOAT128
+#include <boost/multiprecision/float128.hpp>
+#endif
+
+template <typename T>
+void test()
+{
+    if constexpr (std::numeric_limits<T>::has_quiet_NaN)
+    {
+        static_assert(!boost::math::ccmath::isfinite(std::numeric_limits<T>::quiet_NaN()), "Wrong response to NAN");
+    }
+
+    static_assert(boost::math::ccmath::isfinite(T(0)), "Wrong response to 0");
+
+    if constexpr (!std::is_integral_v<T>)
+    {
+        static_assert(boost::math::ccmath::isfinite((std::numeric_limits<T>::min)()/2), "Wrong response to subnormal");
+        static_assert(!boost::math::ccmath::isfinite(std::numeric_limits<T>::infinity()), "Wrong response to infinity");
+    }
+    else
+    {
+        // Integer types define infinity as 0
+        // https://en.cppreference.com/w/cpp/types/numeric_limits/infinity
+        static_assert(boost::math::ccmath::isfinite(std::numeric_limits<T>::infinity()), "Wrong response to infinity");
+    }
+}
+
+#ifndef BOOST_MATH_NO_CONSTEXPR_DETECTION
+int main()
+{
+    test<float>();
+    test<double>();
+
+    #ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
+    test<long double>();
+    #endif
+
+    #if defined(BOOST_HAS_FLOAT128) && !defined(BOOST_MATH_USING_BUILTIN_CONSTANT_P)
+    test<boost::multiprecision::float128>();
+    #endif
+
+    test<int>();
+    test<unsigned>();
+    test<long>();
+    test<std::int32_t>();
+    test<std::int64_t>();
+    test<std::uint32_t>();
+
+    return 0;
+}
+#else
+int main()
+{
+    return 0;
+}
+#endif

test/ccmath_isnormal_test.cpp

@@ -0,0 +1,65 @@
+//  (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)
+
+#include <cmath>
+#include <cfloat>
+#include <cstdint>
+#include <limits>
+#include <type_traits>
+#include <boost/math/ccmath/isnormal.hpp>
+
+#ifdef BOOST_HAS_FLOAT128
+#include <boost/multiprecision/float128.hpp>
+#endif
+
+// Determines if the given argument is normal, i.e. is neither zero, subnormal, infinite nor NaN.
+template <typename T>
+void test()
+{
+    if constexpr (std::numeric_limits<T>::has_quiet_NaN)
+    {
+        static_assert(!boost::math::ccmath::isnormal(std::numeric_limits<T>::quiet_NaN()), "Wrong response to quiet NAN");
+    }
+
+    static_assert(!boost::math::ccmath::isnormal(T(0)), "Wrong response to 0");
+
+    if constexpr (!std::is_integral_v<T>)
+    {
+        static_assert(!boost::math::ccmath::isnormal((std::numeric_limits<T>::min)() / 2), "Wrong response to subnormal");
+        static_assert(!boost::math::ccmath::isnormal(std::numeric_limits<T>::infinity()), "Wrong response to infinity");
+    }
+
+    static_assert(boost::math::ccmath::isnormal(T(1)), "Wrong response to normal number");
+}
+
+#ifndef BOOST_MATH_NO_CONSTEXPR_DETECTION
+int main()
+{
+    test<float>();
+    test<double>();
+
+    #ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
+    test<long double>();
+    #endif
+
+    #if defined(BOOST_HAS_FLOAT128) && !defined(BOOST_MATH_USING_BUILTIN_CONSTANT_P)
+    test<boost::multiprecision::float128>();
+    #endif
+
+    test<int>();
+    test<unsigned>();
+    test<long>();
+    test<std::int32_t>();
+    test<std::int64_t>();
+    test<std::uint32_t>();
+
+    return 0;
+}
+#else
+int main()
+{
+    return 0;
+}
+#endif

test/compile_test/ccmath_isfinite_incl_test.cpp

@@ -0,0 +1,16 @@
+//  (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)
+
+#include <boost/math/ccmath/isfinite.hpp>
+#include "test_compile_result.hpp"
+
+void compile_and_link_test()
+{
+   check_result<bool>(boost::math::ccmath::isfinite(1.0f));
+   check_result<bool>(boost::math::ccmath::isfinite(1.0));
+#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
+   check_result<bool>(boost::math::ccmath::isfinite(1.0l));
+#endif
+}

test/compile_test/ccmath_isnormal_incl_test.cpp

@@ -0,0 +1,16 @@
+//  (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)
+
+#include <boost/math/ccmath/isnormal.hpp>
+#include "test_compile_result.hpp"
+
+void compile_and_link_test()
+{
+   check_result<bool>(boost::math::ccmath::isnormal(1.0f));
+   check_result<bool>(boost::math::ccmath::isnormal(1.0));
+#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
+   check_result<bool>(boost::math::ccmath::isnormal(1.0l));
+#endif
+}