Proper SFINAE usage on PopCount

include/zeus/Math.hpp

@@ -94,21 +94,28 @@ float fastSinF(float val);
 int floorPowerOfTwo(int x);
 int ceilingPowerOfTwo(int x);
 
-template <class T>
+template <typename U>
-inline int PopCount(T x)
+typename std::enable_if<!std::is_enum<U>::value && std::is_integral<U>::value, int>::type
+PopCount(U x)
 {
-    using U = std::make_unsigned_t<std::conditional_t<std::is_enum<T>::value, std::underlying_type_t<T>, T>>;
-    U cx = U(x);
     const U m1  = U(0x5555555555555555); //binary: 0101...
     const U m2  = U(0x3333333333333333); //binary: 00110011..
     const U m4  = U(0x0f0f0f0f0f0f0f0f); //binary:  4 zeros,  4 ones ...
     const U h01 = U(0x0101010101010101); //the sum of 256 to the power of 0,1,2,3...
 
-    cx -= (cx >> 1) & m1;             //put count of each 2 bits into those 2 bits
+    x -= (x >> 1) & m1;             //put count of each 2 bits into those 2 bits
-    cx = (cx & m2) + ((cx >> 2) & m2); //put count of each 4 bits into those 4 bits
+    x = (x & m2) + ((x >> 2) & m2); //put count of each 4 bits into those 4 bits
-    cx = (cx + (cx >> 4)) & m4;        //put count of each 8 bits into those 8 bits
+    x = (x + (x >> 4)) & m4;        //put count of each 8 bits into those 8 bits
-    return (cx * h01) >> ((sizeof(U)-1)*8);  //returns left 8 bits of x + (x<<8) + (x<<16) + (x<<24) + ...
+    return (x * h01) >> ((sizeof(U)-1)*8);  //returns left 8 bits of x + (x<<8) + (x<<16) + (x<<24) + ...
 }
+
+template <typename E>
+typename std::enable_if<std::is_enum<E>::value, int>::type
+PopCount(E e)
+{
+    return PopCount(static_cast<typename std::underlying_type<E>::type>(e));
+}
+
 }
 
 #endif // MATH_HPP