add math: reminder, rem_quo(same as remquo)

sprout/math/frac_int.hpp

@@ -0,0 +1,45 @@
+#ifndef SPROUT_MATH_FRAC_INT_HPP
+#define SPROUT_MATH_FRAC_INT_HPP
+
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/math/detail/config.hpp>
+#include <sprout/math/integer_part.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
+#include <sprout/utility/pair/pair.hpp>
+
+namespace sprout {
+	namespace math {
+		namespace detail {
+			template<typename T>
+			inline SPROUT_CONSTEXPR sprout::pair<T, T>
+			frac_int_impl(T x, T ipart) {
+				return sprout::pair<T, T>(x - ipart, ipart);
+			}
+
+			template<
+				typename FloatType,
+				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+			>
+			inline SPROUT_CONSTEXPR sprout::pair<FloatType, FloatType>
+			frac_int(FloatType x) {
+				return sprout::math::detail::frac_int_impl(x, sprout::math::integer_part(x));
+			}
+
+			template<
+				typename IntType,
+				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+			>
+			inline SPROUT_CONSTEXPR sprout::pair<double, double>
+			frac_int(IntType x) {
+				return sprout::math::detail::frac_int(static_cast<double>(x));
+			}
+		}	// namespace detail
+
+		using sprout::math::detail::frac_int;
+	}	// namespace math
+
+	using sprout::math::frac_int;
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_MATH_FRAC_INT_HPP