Hello, because of a bug[1] in GCC 13 and earlier versions, the #include of quadmath.h in multiprecision/cpp_bin_float.hpp did not fail even when the header file was not present on the system and compilation succeeded as long as nothing from the header file was actually needed. The bug has been fixed in GCC 14 which all of a sudden leads to new build requirements and failures such as [2]. Examining this build failure, I noticed that in math/special_functions/fpclassify.hpp (which is indirectly included from multiprecision/cpp_bin_float.hpp) the existence of the header file is specifically tested and macro BOOST_MATH_HAS_QUADMATH_H is defined or not accordingly. So I wanted to ask the question in the $subject. Could, or perhaps even should the include (together with its uses introduced in commit 4911125248bd) be guarded also by BOOST_MATH_HAS_QUADMATH_H and not just by BOOST_HAS_FLOAT128? Thank you, Martin [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80753 [2] https://bugzilla.opensuse.org/show_bug.cgi?id=1225861#c7