From 30be128a84e0fb4722519ee80be84702bcf8f763 Mon Sep 17 00:00:00 2001
From: ckormanyos <ckormanyos@yahoo.com>
Date: Sat, 12 Apr 2025 11:15:13 +0200
Subject: [PATCH] Repair test 1255 and adapt to double

---
 test/git_issue_1255.cpp | 45 ++++++++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 14 deletions(-)

diff --git a/test/git_issue_1255.cpp b/test/git_issue_1255.cpp
index 56d692331..133986a2d 100644
--- a/test/git_issue_1255.cpp
+++ b/test/git_issue_1255.cpp
@@ -3,28 +3,45 @@
 //  Boost Software License, Version 1.0. (See accompanying file
 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
+// See also: https://godbolt.org/z/nhMsKb8Yr
+
 #include <boost/core/lightweight_test.hpp>
 #include <boost/math/special_functions/bessel.hpp>
 
 #include <cmath>
 #include <limits>
 
+namespace local
+{
+  template<typename FloatType>
+  auto test() -> void
+  {
+    using float_type = FloatType;
+
+    using std::ldexp;
+
+    // N[BesselY[-1, (2875/1000)  (2^(-128))], 51]
+    // 7.53497332069250908152363321534337029122980775749906*10^37
+
+    const float_type x { static_cast<float_type>(ldexp(2.875L, -128)) };
+
+    constexpr float_type ctrl { static_cast<float_type>(7.53497332069250908152363321534337029122980775749906E37L) };
+
+    const float_type result = ::boost::math::cyl_neumann(-1, x);
+
+    constexpr float_type tol = std::numeric_limits<float_type>::epsilon() * 16;
+
+    using ::std::fabs;
+
+    BOOST_TEST(result > 0);
+    BOOST_TEST(fabs(1 - (result / ctrl)) < tol);
+  }
+} // namespace local
+
 auto main() -> int
 {
-  using float_type = float;
-
-  const float_type x { 0x1.03ebbp-128F };
-
-  const float_type ctrl { 0x1.41085ep+127F };
-
-  const float_type result = ::boost::math::cyl_neumann(-1, x);
-
-  const float_type tol = std::numeric_limits<float_type>::epsilon() * 16;
-
-  using std::fabs;
-
-  BOOST_TEST(result > 0);
-  BOOST_TEST(fabs(1 - (result / ctrl)) < tol);
+  local::test<double>();
+  local::test<long double>();
 
   return boost::report_errors();
 }