Remove redundant condition from capture_stage()

[stockfish] / src / position.h

diff --git a/src/position.h b/src/position.h
index c82c7a8bf87acbfc6c4c683599ce8c57a4dace99..cc606a5ab00af8dcb0d7a6dbed9ec326997b7222 100644 (file)
--- a/src/position.h
+++ b/src/position.h
@@ -126,6 +126,7 @@ public:
   bool legal(Move m) const;
   bool pseudo_legal(const Move m) const;
   bool capture(Move m) const;
+  bool capture_stage(Move m) const;
   bool gives_check(Move m) const;
   Piece moved_piece(Move m) const;
   Piece captured_piece() const;
@@ -383,8 +384,16 @@ inline bool Position::is_chess960() const {
 
 inline bool Position::capture(Move m) const {
   assert(is_ok(m));
-  // Castling is encoded as "king captures rook"
-  return (!empty(to_sq(m)) && type_of(m) != CASTLING) || type_of(m) == EN_PASSANT;
+  return     (!empty(to_sq(m)) && type_of(m) != CASTLING)
+          ||  type_of(m) == EN_PASSANT;
+}
+
+// returns true if a move is generated from the capture stage
+// having also queen promotions covered, i.e. consistency with the capture stage move generation
+// is needed to avoid the generation of duplicate moves.
+inline bool Position::capture_stage(Move m) const {
+  assert(is_ok(m));
+  return  capture(m) || promotion_type(m) == QUEEN;
 }
 
 inline Piece Position::captured_piece() const {