Added bit rotation functions

include/BitBoard.h

@@ -21,6 +21,13 @@ class BitBoard
 
     bool m_isBlacksTurn = true;
 
+    /* Class member functions */
+
+    // These are basic 32 bit rotation functions
+    // Details here: http://stackoverflow.com/questions/776508/best-practices-for-circular-shift-rotate-operations-in-c
+    uint32_t const rotl32 (uint32_t n, unsigned int c);
+    uint32_t const rotr32 (uint32_t n, unsigned int c);
+
 public:
 
 };

src/BitBoard.cpp

@@ -1 +1,19 @@
+#include <cstdint>
+#include <limits.h>
 #include "BitBoard.h"
+
+uint32_t const BitBoard::rotl32 (uint32_t n, unsigned int c)
+{
+  const unsigned int mask = (CHAR_BIT*sizeof(n)-1);
+
+   c &= mask;  // avoid undef behaviour with NDEBUG.  0 overhead for most types / compilers
+    return (n<<c) | (n>>( (-c)&mask ));
+}
+
+uint32_t const BitBoard::rotr32 (uint32_t n, unsigned int c)
+{
+  const unsigned int mask = (CHAR_BIT*sizeof(n)-1);
+
+   c &= mask;  // avoid undef behaviour with NDEBUG.  0 overhead for most types / compilers
+    return (n>>c) | (n<<( (-c)&mask ));
+}