Make Square and Bitboard operators commutative

[stockfish] / src / bitboard.h

diff --git a/src/bitboard.h b/src/bitboard.h
index ef5c4fa304ab1beb366077a36720dab9782744d4..8d748eeed8615628ddd4b044df9c34aef4fcaeff 100644 (file)
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -119,6 +119,12 @@ inline Bitboard  operator^( Bitboard  b, Square s) { return b ^  square_bb(s); }
 inline Bitboard& operator|=(Bitboard& b, Square s) { return b |= square_bb(s); }
 inline Bitboard& operator^=(Bitboard& b, Square s) { return b ^= square_bb(s); }
 
+inline Bitboard  operator&(Square s, Bitboard b) { return b & s; }
+inline Bitboard  operator|(Square s, Bitboard b) { return b | s; }
+inline Bitboard  operator^(Square s, Bitboard b) { return b ^ s; }
+
+inline Bitboard  operator|(Square s, Square s2) { return square_bb(s) | square_bb(s2); }
+
 constexpr bool more_than_one(Bitboard b) {
   return b & (b - 1);
 }
@@ -376,10 +382,9 @@ inline Square pop_lsb(Bitboard* b) {
 }
 
 
-/// frontmost_sq() and backmost_sq() return the most/least advanced square in
-/// the given bitboard relative to the given color.
-
-inline Square frontmost_sq(Color c, Bitboard b) { return c == WHITE ? msb(b) : lsb(b); }
-inline Square  backmost_sq(Color c, Bitboard b) { return c == WHITE ? lsb(b) : msb(b); }
+/// frontmost_sq() returns the most advanced square for the given color
+inline Square frontmost_sq(Color c, Bitboard b) {
+  return c == WHITE ? msb(b) : lsb(b);
+}
 
 #endif // #ifndef BITBOARD_H_INCLUDED