From eef497efea6df4cc5ec1a704c0ecc1ee122b76a9 Mon Sep 17 00:00:00 2001
From: jzmaddock <john@johnmaddock.co.uk>
Date: Fri, 9 Feb 2024 18:25:31 +0000
Subject: [PATCH] Make bessel_k_prime integer order aware.

---
 .../detail/bessel_derivatives_linear.hpp         |  8 ++++++++
 test/test_bessel_k_prime.hpp                     | 16 ++++++++--------
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/include/boost/math/special_functions/detail/bessel_derivatives_linear.hpp b/include/boost/math/special_functions/detail/bessel_derivatives_linear.hpp
index 42abbc15b..a391c33bf 100644
--- a/include/boost/math/special_functions/detail/bessel_derivatives_linear.hpp
+++ b/include/boost/math/special_functions/detail/bessel_derivatives_linear.hpp
@@ -75,6 +75,14 @@ inline T bessel_k_derivative_linear(T v, T x, const bessel_int_tag& tag, Policy
    return result + result2;
 }
 
+template <class T, class Policy>
+inline T bessel_k_derivative_linear(T v, T x, const bessel_maybe_int_tag&, Policy pol)
+{
+   if (floor(v) == v)
+      return bessel_k_derivative_linear(v, x, bessel_int_tag(), pol);
+   return bessel_k_derivative_linear(v, x, bessel_no_int_tag(), pol);
+}
+
 template <class T, class Tag, class Policy>
 inline T bessel_y_derivative_linear(T v, T x, Tag tag, Policy pol)
 {
diff --git a/test/test_bessel_k_prime.hpp b/test/test_bessel_k_prime.hpp
index 7f0eb6151..f43728c11 100644
--- a/test/test_bessel_k_prime.hpp
+++ b/test/test_bessel_k_prime.hpp
@@ -185,31 +185,31 @@ void test_bessel(T, const char* name)
     {
        static const std::array<std::array<T, 3>, 8> coverage_data = { {
 #if LDBL_MAX_10_EXP > 310
-           {{ SC_(20), static_cast<T>(ldexp(T(1), -45)), SC_(-3.793503044583520787322174911740831752794438746336004555076e308) }},
+           {{ SC_(20.0), static_cast<T>(ldexp(T(1), -45)), SC_(-3.793503044583520787322174911740831752794438746336004555076e308) }},
            {{ SC_(20.125), static_cast<T>(ldexp(T(1), -45)), SC_(-2.979220621533376610700938325572770408419207521624698386062e310) }},
 #else
-           {{ SC_(20), static_cast<T>(ldexp(T(1), -45)), -std::numeric_limits<T>::infinity() }},
+           {{ SC_(20.0), static_cast<T>(ldexp(T(1), -45)), -std::numeric_limits<T>::infinity() }},
            {{ SC_(20.125), static_cast<T>(ldexp(T(1), -45)), -std::numeric_limits<T>::infinity() }},
 #endif
 #if LDBL_MAX_10_EXP > 346
-           {{ SC_(20), static_cast<T>(ldexp(T(1), -51)), SC_(-3.227155487331667007856383940813742118802894409545345203104e346) }},
+           {{ SC_(20.0), static_cast<T>(ldexp(T(1), -51)), SC_(-3.227155487331667007856383940813742118802894409545345203104e346) }},
            {{ SC_(20.125), static_cast<T>(ldexp(T(1), -51)), SC_(-4.262404050083097364466577035647085801041781477814968803189e348) }},
 #else
-           {{ SC_(20), static_cast<T>(ldexp(T(1), -51)), -std::numeric_limits<T>::infinity() }},
+           {{ SC_(20.0), static_cast<T>(ldexp(T(1), -51)), -std::numeric_limits<T>::infinity() }},
            {{ SC_(20.125), static_cast<T>(ldexp(T(1), -51)), -std::numeric_limits<T>::infinity() }},
 #endif
 #if LDBL_MAX_10_EXP > 4971
-           {{ SC_(20), static_cast<T>(ldexp(T(1), -778)), SC_(-2.15657066125095338369788943003323297569772178814715617602e4942) }},
+           {{ SC_(20.0), static_cast<T>(ldexp(T(1), -778)), SC_(-2.15657066125095338369788943003323297569772178814715617602e4942) }},
            {{ SC_(20.125), static_cast<T>(ldexp(T(1), -778)), SC_(-6.46694658438021098575183049117626387183087801364084017400e4971) }},
 #else
-           {{ SC_(20), static_cast<T>(ldexp(T(1), -778)), -std::numeric_limits<T>::infinity() }},
+           {{ SC_(20.0), static_cast<T>(ldexp(T(1), -778)), -std::numeric_limits<T>::infinity() }},
            {{ SC_(20.125), static_cast<T>(ldexp(T(1), -778)), -std::numeric_limits<T>::infinity() }},
 #endif
 #if LDBL_MAX_10_EXP > 5493
-           {{ SC_(20), static_cast<T>(ldexp(T(1), -860)), SC_(-5.09819245599453059425108127687500966644642217657888061634e5460) }},
+           {{ SC_(20.0), static_cast<T>(ldexp(T(1), -860)), SC_(-5.09819245599453059425108127687500966644642217657888061634e5460) }},
            {{ SC_(20.125), static_cast<T>(ldexp(T(1), -860)), SC_(-1.86169813082884487070647108868007382252541071831005047607e5493) }},
 #else
-           {{ SC_(20), static_cast<T>(ldexp(T(1), -860)), -std::numeric_limits<T>::infinity() }},
+           {{ SC_(20.0), static_cast<T>(ldexp(T(1), -860)), -std::numeric_limits<T>::infinity() }},
            {{ SC_(20.125), static_cast<T>(ldexp(T(1), -860)), -std::numeric_limits<T>::infinity() }},
 #endif
        } };