fix some compiler warnings

src/Core/Board.cpp

@@ -20,10 +20,10 @@ Board::Board(int width, int height) :
 }
 
 void Board::changeBlock(const Position& position, Block block) {
-    if (position.x < 0 || position.x >= this->width || position.y < 0) return;
+    if (position.x < 0 || static_cast<unsigned>(position.x) >= this->width || position.y < 0) return;
 
     // resize the grid if needed
-    if (position.y >= this->grid.size()) {
+    if (static_cast<unsigned>(position.y) >= this->grid.size()) {
         for (int j = this->grid.size(); j <= position.y; j++) {
             this->grid.push_back(this->emptyRow);
         }
@@ -34,7 +34,7 @@ void Board::changeBlock(const Position& position, Block block) {
 
 void Board::insertRow(int height, int holePosition, Block blockType) {
     std::vector<Block> insertedRow;
-    for (int i = 0; i < this->width; i++) {
+    for (unsigned i = 0; i < this->width; i++) {
         if (i == holePosition) {
             insertedRow.push_back(NOTHING);
         }
@@ -51,7 +51,7 @@ int Board::clearRows() {
     int clearedLines = 0;
     for (int j = this->grid.size() - 1; j >= 0; j--) {
         bool lineIsFull = true;
-        int i = 0;
+        unsigned i = 0;
         while (lineIsFull && (i < width)) {
             if (this->grid.at(j).at(i) == NOTHING) {
                 lineIsFull = false;

src/Core/Board.h

@@ -13,8 +13,8 @@ class Board {
     private:
         std::vector<std::vector<Block>> grid; // the grid, (0,0) is downleft
         std::vector<Block> emptyRow;          // an empty row of blocks
-        int width;                            // the width of the grid
-        int height;                           // the base height of the grid, which can extend indefinitely
+        unsigned width;                            // the width of the grid
+        unsigned height;                           // the base height of the grid, which can extend indefinitely
 
     public:
         /**

src/Core/PiecesList.cpp

@@ -27,12 +27,12 @@ PiecesList::PiecesList() {
     this->pushBackEmptyVectors();
 }
 
-bool PiecesList::loadPieces(int max_size) {
+bool PiecesList::loadPieces(unsigned max_size) {
     if (max_size < 1) return false;
     if (max_size <= this->highestLoadedSize) return true;
 
     PiecesFiles piecesFiles;
-    for (int i = this->highestLoadedSize + 1; i <= max_size; i++) {
+    for (unsigned i = this->highestLoadedSize + 1; i <= max_size; i++) {
         if (!piecesFiles.loadPieces(i, this->loadedPieces.at(i), this->convexPieces.at(i), this->holelessPieces.at(i), this->otherPieces.at(i))) {
             return false;
         }
@@ -45,14 +45,14 @@ bool PiecesList::loadPieces(int max_size) {
     return true;
 }
 
-bool PiecesList::selectPiece(int size, int number) {
+bool PiecesList::selectPiece(unsigned size, unsigned number) {
     if (size < 1 || size > this->highestLoadedSize || number >= this->loadedPieces.at(size).size()) return false;
 
     this->selectedPieces.push_back(std::pair<int, int>(size, number));
     return true;
 }
 
-bool PiecesList::selectAllPieces(int size) {
+bool PiecesList::selectAllPieces(unsigned size) {
     if (size < 1 || size > this->highestLoadedSize) return false;
 
     for (int i = 0; i < this->loadedPieces.at(size).size(); i++) {

src/Core/PiecesList.h

@@ -13,7 +13,7 @@
  */
 class PiecesList {
     private:
-        int highestLoadedSize;                           // the highest size of pieces currently loaded
+        unsigned highestLoadedSize;                           // the highest size of pieces currently loaded
         std::vector<std::vector<Piece>> loadedPieces;    // every loaded pieces by size
         std::vector<std::vector<int>> convexPieces;      // the list of convex loaded pieces by size
         std::vector<std::vector<int>> holelessPieces;    // the list of holeless loaded pieces by size
@@ -33,19 +33,19 @@ class PiecesList {
          * Makes the list load all pieces up to the specified size
          * @return If all pieces up to the specified size are correctly loaded
          */
-        [[nodiscard]] bool loadPieces(int max_size);
+        [[nodiscard]] bool loadPieces(unsigned max_size);
 
         /**
          * Selects the specified piece
          * @return If the piece could be selected
          */
-        bool selectPiece(int size, int number);
+        bool selectPiece(unsigned size, unsigned number);
 
         /**
          * Selects all pieces of the specified size
          * @return If the pieces could be selected
          */
-        bool selectAllPieces(int size);
+        bool selectAllPieces(unsigned size);
 
         /**
          * Selects all convex pieces of the specified size