Remove MSVC fallback that was inconsistent with every other impl

include/ccmath/detail/compare/signbit.hpp

@@ -43,14 +43,6 @@
  #endif
 #endif
 
-// This is are last resort for MSVC. This is constexpr, but it is not static_assert-able.
-// TODO: Decide if it is improper to allow this inconsistent behavior for MSVC 19.26 and earlier against how every other approach behaves.
-#if defined(_MSVC_VER) && !defined(CCMATH_HAS_CONSTEXPR_BUILTIN_BIT_CAST) && !defined(CCMATH_HAS_CONSTEXPR_SIGNBIT) && \
- !defined(CCMATH_HAS_CONSTEXPR_BUILTIN_COPYSIGN)
- #define CCMATH_MSVC_DOES_NOT_HAVE_ASSERTABLE_CONSTEXPR_SIGNBIT
- #include <cfloat> // for _fpclass and _FPCLASS_NZ
-#endif
-
 namespace ccm
 {
  /**
@@ -61,13 +53,7 @@ namespace ccm
  *
  * @note This function has multiple implementations based on the compiler and the version of
  * the the compiler used. With nearly all implementations, this function is fully constexpr and will return
- * the same values as std::signbit along with being static_assert-able. The only exception is MSVC 19.26 and earlier
- * and unknown compilers that support none of possible implementations.
- *
- * @note ccm::signbit by default will use std::signbit if using C++23 or later.
- *
- * @warning ccm::signbit will not work with static_assert on MSVC 19.26 and earlier. This is due to the fact that
- * MSVC does not provide a constexpr signbit until 19.27. This is a limitation of MSVC and not ccmath.
+ * the same values as std::signbit along with being static_assert-able.
  *
  * @warning ccm::signbit currently is only ensured to work on little-endian systems. There is currently no guarantee this it will work on big-endian
  * systems.
@@ -107,12 +93,6 @@ namespace ccm
  }
 
  return x < static_cast<T>(0);
-#elif defined(CCMATH_MSVC_DOES_NOT_HAVE_ASSERTABLE_CONSTEXPR_SIGNBIT)
- // If we don't have access to MSVC 19.27 or later, we can use _fpclass and _FPCLASS_NZ to
- // check for the sign of zero. This is is constexpr, but it is not static_assert-able.
- // TODO: Decide if it is improper to allow this inconsistent behavior for MSVC 19.26 and earlier against how every other approach behaves with
- // ccm::signbit.
- return ((x == static_cast<T>(0)) ? (_fpclass(x) == _FPCLASS_NZ) : (x < T(0))); // This won't work in static assertions
 #else
  static_assert(false, "ccm::signbit is not implemented for this compiler. Please report this issue to the dev!");
  return false;
@@ -167,7 +147,3 @@ namespace ccm
 #ifdef CCMATH_HAS_CONSTEXPR_BUILTIN_COPYSIGN
  #undef CCMATH_HAS_CONSTEXPR_BUILTIN_COPYSIGN
 #endif
-
-#ifdef CCMATH_MSVC_DOES_NOT_HAVE_ASSERTABLE_CONSTEXPR_SIGNBIT
- #undef CCMATH_MSVC_DOES_NOT_HAVE_ASSERTABLE_CONSTEXPR_SIGNBIT
-#endif