diff --git a/src/core/a.out b/src/core/a.out
deleted file mode 100755
index 7ac7b3c..0000000
Binary files a/src/core/a.out and /dev/null differ
diff --git a/src/core/board2d.cpp b/src/core/board2d.cpp
index 860846e..1d274d3 100644
--- a/src/core/board2d.cpp
+++ b/src/core/board2d.cpp
@@ -20,13 +20,13 @@ void Board2D::add_unit(const Coord c)
     if (!(space.capacity >= space.value)) throw InvalidMove {"Space is overloaded"};
 
     space.value++;
-    _units[space.owner]++;
-    cout << "total: " << _units[space.owner] << endl;
+    units[space.owner]++;
+    cout << "total: " << units[space.owner] << endl;
 }
 
 auto Board2D::begin() const noexcept -> const_iterator
 {
-    return _spaces.cbegin();
+    return spaces.cbegin();
 }
 
 void Board2D::capture(const Coord c, const Player p) noexcept
@@ -35,47 +35,47 @@ void Board2D::capture(const Coord c, const Player p) noexcept
     if (s.owner != p) {
         cout << "= P" << static_cast<int>(p) << " captures " << s.coord.x << ","
              << s.coord.y << " : +" << s.value << endl;
-        _units[s.owner] -= s.value;
-        _units[p] += s.value;
+        units[s.owner] -= s.value;
+        units[p] += s.value;
         s.owner = p;
     }
 }
 
 auto Board2D::end() const noexcept -> const_iterator
 {
-    return _spaces.cend();
+    return spaces.cend();
 }
 
-void Board2D::init(const size_type w, const size_type h)
+void Board2D::init(const size_type w_, const size_type h_)
 {
-    _width  = w;
-    _height = h;
+    w  = w_;
+    h = h_;
 
-    _spaces.reserve(w * h); // NOLINT
-    for (size_type y = 0; y < h; y++) {
-        for (size_type x = 0; x < w; x++) {
-            _spaces.push_back(Coord {x, y});
-            if (x == 0 || x == w - 1) {
-                if (y == 0 || y == h - 1) {
-                    _spaces.back().capacity = 1;
+    spaces.reserve(w_ * h_); // NOLINT
+    for (size_type y = 0; y < h_; y++) {
+        for (size_type x = 0; x < w_; x++) {
+            spaces.push_back(Coord {x, y});
+            if (x == 0 || x == w_ - 1) {
+                if (y == 0 || y == h_ - 1) {
+                    spaces.back().capacity = 1;
                 }
                 else {
-                    _spaces.back().capacity = 2;
+                    spaces.back().capacity = 2;
                 }
             }
             else {
-                if (y == 0 || y == h - 1) {
-                    _spaces.back().capacity = 2;
+                if (y == 0 || y == h_ - 1) {
+                    spaces.back().capacity = 2;
                 }
                 else {
-                    _spaces.back().capacity = 3;
+                    spaces.back().capacity = 3;
                 }
             }
         }
     }
 
-    _units.emplace(Player::P1, 0);
-    _units.emplace(Player::P2, 0);
+    units.emplace(Player::P1, 0);
+    units.emplace(Player::P2, 0);
 }
 
 auto Board2D::is_overloaded(Coord c) const noexcept -> bool
@@ -121,16 +121,16 @@ auto Board2D::neighbours(const Coord c) const noexcept -> vector<Coord>
     vector<Coord> nghbrs;
 
     if (c.x > 0) nghbrs.emplace_back(Coord {c.x - 1, c.y});
-    if (c.x < _width - 1) nghbrs.emplace_back(Coord {c.x + 1, c.y});
+    if (c.x < w - 1) nghbrs.emplace_back(Coord {c.x + 1, c.y});
     if (c.y > 0) nghbrs.emplace_back(Coord {c.x, c.y - 1});
-    if (c.y < _height - 1) nghbrs.emplace_back(Coord {c.x, c.y + 1});
+    if (c.y < h - 1) nghbrs.emplace_back(Coord {c.x, c.y + 1});
 
     return nghbrs;
 }
 
 auto Board2D::operator()(const Coord c) const noexcept -> const Board2D::Space&
 {
-    return _spaces.at(coord2idx(c));
+    return spaces.at(coord2idx(c));
 }
 
 void Board2D::remove_unit(const Coord c)
@@ -139,20 +139,20 @@ void Board2D::remove_unit(const Coord c)
     const auto owner = s.owner;
     if (s.value > 1) {
         s.value--;
-        _units[owner]--;
+        units[owner]--;
     }
     else if (s.value == 1) {
         s.reset();
-        _units[owner]--;
+        units[owner]--;
     }
     else throw logic_error("Space is empty");
     cout << "- remove " << c.x << "," << c.y << " "
-         << "total: " << _units[owner] << endl;
+         << "total: " << units[owner] << endl;
 }
 
 auto Board2D::size() const noexcept -> pair<size_type, size_type>
 {
-    return {_width, _height};
+    return {w, h};
 }
 
 auto Board2D::spread(const Coord src, const vector<Coord>& targets, const Player p)
@@ -188,7 +188,7 @@ auto Board2D::winner(const Board2D& b) noexcept -> Player
 {
     Player winner {Player::NONE};
 
-    for (auto [key, value] : b._units) {
+    for (auto [key, value] : b.units) {
         if (value > 0) {
             if (winner == Player::NONE) winner = key;
             else return Player::NONE;
@@ -200,15 +200,15 @@ auto Board2D::winner(const Board2D& b) noexcept -> Player
 
 auto Board2D::at(const Coord c) noexcept -> Space&
 {
-    return _spaces.at(coord2idx(c));
+    return spaces.at(coord2idx(c));
 }
 
 auto Board2D::at(const Coord c) const noexcept -> const Space&
 {
-    return _spaces.at(coord2idx(c));
+    return spaces.at(coord2idx(c));
 }
 
 auto Board2D::coord2idx(const Coord c) const noexcept -> size_type
 {
-    return c.y * _width + c.x;
+    return c.y * w + c.x;
 }
diff --git a/src/core/board2d.hpp b/src/core/board2d.hpp
index ed8f2b6..98abee1 100644
--- a/src/core/board2d.hpp
+++ b/src/core/board2d.hpp
@@ -51,16 +51,13 @@ namespace core
         Board2D() = default;
         Board2D(size_type, size_type);
 
-        void               add_unit(Coord);
         [[nodiscard]] auto begin() const noexcept -> const_iterator;
-        void               capture(Coord, Player) noexcept;
         [[nodiscard]] auto end() const noexcept -> const_iterator;
         void               init(size_type, size_type);
         [[nodiscard]] auto is_overloaded(Coord) const noexcept -> bool;
         auto               move(Coord, Player) -> Generator<std::pair<Space, Player>>;
         [[nodiscard]] auto neighbours(Coord) const noexcept -> std::vector<Coord>;
         [[nodiscard]] auto operator()(Coord) const noexcept -> const Space&;
-        void               remove_unit(Coord);
         [[nodiscard]] auto size() const noexcept -> std::pair<size_type, size_type>;
         auto spread(Coord, const std::vector<Coord>&, Player) -> Generator<Space>;
         [[nodiscard]] auto winner() const noexcept -> Player;
@@ -68,14 +65,17 @@ namespace core
         [[nodiscard]] static auto winner(const Board2D&) noexcept -> Player;
 
     private:
-        size_type             _height;
-        Spaces                _spaces;
-        std::map<Player, int> _units;
-        size_type             _width;
+        size_type             h;
+        Spaces                spaces;
+        std::map<Player, int> units;
+        size_type             w;
 
+        void               add_unit(Coord);
         [[nodiscard]] auto at(Coord) noexcept -> Space&;
         [[nodiscard]] auto at(Coord) const noexcept -> const Space&;
+        void               capture(Coord, Player) noexcept;
         [[nodiscard]] auto coord2idx(Coord) const noexcept -> size_type;
+        void               remove_unit(Coord);
     };
 }
 
diff --git a/src/core/generator.hpp.gch b/src/core/generator.hpp.gch
deleted file mode 100644
index a50992a..0000000
Binary files a/src/core/generator.hpp.gch and /dev/null differ