Move logic changes

src/board.rs

@@ -159,17 +159,19 @@ impl Board {
         }
     }
 
-    pub fn what_if(&self, i: usize, j: usize, piece: Piece) -> Option<(Self, usize)> {
+    pub fn what_if(&self, i: usize, j: usize, piece: Piece) -> Option<Self> {
         if self.get(i, j).is_some() {
             return None;
         }
+
         let mut self_copy = *self;
         self_copy.place_unchecked(i, j, piece);
         let how_many_prop = self_copy.propegate_from(i, j);
         if how_many_prop == 0 {
             return None;
         }
-        Some((self_copy, how_many_prop))
+
+        Some(self_copy)
     }
 
     pub fn would_prop(&self, i: usize, j: usize, piece: Piece) -> bool {
@@ -178,10 +180,8 @@ impl Board {
 
     pub fn place(&mut self, i: usize, j: usize, piece: Piece) -> Result<(), &'static str> {
         if let Some(what_if_result) = self.what_if(i, j, piece) {
-            if what_if_result.1 > 0 {
-                *self = what_if_result.0;
-                return Ok(());
-            }
+            *self = what_if_result;
+            return Ok(());
         }
         Err("move would not propegate")
     }
@@ -203,9 +203,6 @@ impl Board {
     /// Propegate piece captures originating from (i, j)
     /// DO NOT USE THIS ALONE, this should be called as a part of
     /// [`Board::place`] or [`Board::place_and_prop_unchecked`]
-    // TODO! this function is responsible for approx 64% of the time spent computing moves in `ComplexAgent`
-    // NOTE! got it down to 24.86% (61.1% decrease) with allocator optimizations
-    // IDEAS: early-exit from each chain so we don't have to call `diag` (which allocs a lot and uses a lot of cycles)
     fn propegate_from_dry(&self, i: usize, j: usize, starting_color: Piece) -> Vec<(usize, usize)> {
         // Longest chain is (BOARD_SIZE - 2) as there needs to be the two pieces containing it
         let mut fill: Vec<(usize, usize)> = Vec::with_capacity((BOARD_SIZE - 2) * 8);