Use occupied_squares() in book_key()

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

diff --git a/src/book.cpp b/src/book.cpp
index 0212317..7cb0863 100644 (file)
--- a/src/book.cpp
+++ b/src/book.cpp
@@ -528,7 +528,7 @@ namespace {
   uint64_t book_key(const Position& pos) {
 
     uint64_t result = 0;
-    Bitboard b = pos.pieces_of_color(WHITE) | pos.pieces_of_color(BLACK);
+    Bitboard b = pos.occupied_squares();
 
     while (b)
     {