add math/classifications.hpp

sprout/math/fpclassify.hpp

@@ -0,0 +1,41 @@
+#ifndef SPROUT_MATH_FPCLASSIFY_HPP
+#define SPROUT_MATH_FPCLASSIFY_HPP
+
+#include <cmath>
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/utility/enabler_if.hpp>
+#include <sprout/math/isnan.hpp>
+#include <sprout/math/isinf.hpp>
+#include <sprout/math/iszero.hpp>
+#include <sprout/math/issubnormal.hpp>
+
+namespace sprout {
+	namespace math {
+		namespace detail {
+			template<
+				typename FloatType,
+				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+			>
+			inline SPROUT_CONSTEXPR int
+			fpclassify(FloatType x) {
+				return sprout::math::isnan(x) ? FP_NAN
+					: sprout::math::isinf(x) ? FP_INFINITE
+					: sprout::math::iszero(x) ? FP_ZERO
+					: sprout::math::detail::issubnormal_or_zero(x) ? FP_SUBNORMAL
+					: FP_NORMAL
+					;
+			}
+		}	// namespace detail
+
+#	if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+		using std::fpclassify;
+#	else
+		using sprout::math::detail::fpclassify;
+#	endif
+	}	// namespace math
+
+	using sprout::math::fpclassify;
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_MATH_FPCLASSIFY_HPP