Define overloads as templates

Author: robincaloudis

libcxx/include/__math/traits.h

@@ -34,27 +34,21 @@ namespace __math {
 #  define _LIBCPP_SIGNBIT_CONSTEXPR
 #endif
 
-// The universal C runtime (UCRT) in the WinSDK provides overloads for all floating point types
-// for std::signbit(). We need to work around it as the compilation would otherwise error out
-// due to duplicated definitions for clang-cl builds.
-#if defined(_LIBCPP_MSVCRT) && defined(_LIBCPP_PREFERRED_OVERLOAD)
-#  define LIBCPP_SIGNBIT_OVERLOAD _LIBCPP_PREFERRED_OVERLOAD
-#else
-#  define LIBCPP_SIGNBIT_OVERLOAD
-#endif
-
-_LIBCPP_NODISCARD inline _LIBCPP_SIGNBIT_CONSTEXPR _LIBCPP_HIDE_FROM_ABI LIBCPP_SIGNBIT_OVERLOAD bool
-signbit(float __x) _NOEXCEPT {
+// The universal C runtime (UCRT) in the WinSDK provides floating point overloads
+// for std::signbit(). By defining our overloads as templates, we can work around
+// this issue as templates are less preferred than non-template functions.
+template <class = void>
+_LIBCPP_NODISCARD inline _LIBCPP_SIGNBIT_CONSTEXPR _LIBCPP_HIDE_FROM_ABI bool signbit(float __x) _NOEXCEPT {
   return __builtin_signbit(__x);
 }
 
-_LIBCPP_NODISCARD inline _LIBCPP_SIGNBIT_CONSTEXPR _LIBCPP_HIDE_FROM_ABI LIBCPP_SIGNBIT_OVERLOAD bool
-signbit(double __x) _NOEXCEPT {
+template <class = void>
+_LIBCPP_NODISCARD inline _LIBCPP_SIGNBIT_CONSTEXPR _LIBCPP_HIDE_FROM_ABI bool signbit(double __x) _NOEXCEPT {
   return __builtin_signbit(__x);
 }
 
-_LIBCPP_NODISCARD inline _LIBCPP_SIGNBIT_CONSTEXPR _LIBCPP_HIDE_FROM_ABI LIBCPP_SIGNBIT_OVERLOAD bool
-signbit(long double __x) _NOEXCEPT {
+template <class = void>
+_LIBCPP_NODISCARD inline _LIBCPP_SIGNBIT_CONSTEXPR _LIBCPP_HIDE_FROM_ABI bool signbit(long double __x) _NOEXCEPT {
   return __builtin_signbit(__x);
 }