C++11 Type Trait Issue

gistfile1.cpp

#ifndef RATIONAL_H
#define RATIONAL_H

/*
 * Standard Includes
 */

#include <type_traits>

/*
 * Project Includes
 */

/*
 * Macros
 */

/*
 * Types
 */

/*
 * Data
 */

/*
 * Classes and Functions
 */

template <typename Type>
class Rational {
	public:
	// The numerator and denominator of the rational number.
	Type n;
	Type d;
	
	/*
	 * Default constructor.
	 */
	inline Rational(Type num = 0, Type den = 1) : n(num), d(den) {}
	
	/*
	 * Copy constructors.
	 */
	template <typename OtherType>
	inline Rational(const Rational<OtherType>& other) : n(other.n), d(other.d) {}

	template <typename NumType, typename = typename std::enable_if<std::is_arithmetic<NumType>::value>::type>
	inline operator NumType () const {
		return (NumType)this->n / (NumType)this->d;
	}
};

/*
 * Comparisons
 */

template <typename NativeType, typename RationalType, typename = typename std::enable_if<std::is_arithmetic<NativeType>::value>::type>
inline bool operator<(const NativeType left, const Rational<RationalType>& right) {
	return (left * right.d) < right.n;
}

template <typename NativeType, typename RationalType, typename = typename std::enable_if<std::is_arithmetic<NativeType>::value>::type>
inline bool operator>(const NativeType left, const Rational<RationalType>& right) {
	return (left * right.d) > right.n;
}

template <typename IntType, typename RationalType>
inline bool operator==(const typename std::enable_if<std::is_integral<IntType>::value, IntType>::type left, const Rational<RationalType>& right) {
	return (left * right.d) == right.n;
}

template <typename FloatType, typename RationalType>
inline bool operator==(const typename std::enable_if<std::is_floating_point<FloatType>::value, FloatType>::type left, const Rational<RationalType>& right) {
	return FP_EQUAL(left, ((FloatType)right));
}

template <typename NativeType, typename RationalType, typename = typename std::enable_if<std::is_arithmetic<NativeType>::value>::type>
inline bool operator!=(const NativeType left, const Rational<RationalType>& right) {
	return !(left == right);
}

template <typename NativeType, typename RationalType, typename = typename std::enable_if<std::is_arithmetic<NativeType>::value>::type>
inline bool operator<=(const NativeType left, const Rational<RationalType>& right) {
	return (left < right) or (left == right);
}

template <typename NativeType, typename RationalType, typename = typename std::enable_if<std::is_arithmetic<NativeType>::value>::type>
inline bool operator>=(const NativeType left, const Rational<RationalType>& right) {
	return (left > right) or (left == right); 
}

#endif // RATIONAL_H