did some stuff to make makefile work... it was

painful

cpp/src/board.cpp

@@ -0,0 +1,77 @@
+#include "board.hpp"
+
+#include <cctype>
+#include <map>
+
+Board* Board::setup_fen_position(std::string fen) {
+    Board* board = new Board();
+    std::map<char, Piece> c2p{
+        {'k', Piece::King},
+        {'p', Piece::Pawn},
+        {'n', Piece::Knigt},
+        {'b', Piece::Bishop},
+        {'r', Piece::Rook},
+        {'q', Piece::Queen},
+    };
+
+    std::string fen_board = fen.substr(0, fen.find(' '));
+    int rank = 7, file = 0;
+    for (char symbol : fen_board) {
+        if (symbol == '/') {
+            file = 0;
+            rank--;
+            continue;
+        }
+
+        if (std::isdigit(symbol))
+            file += symbol - '0';
+        else {
+            Colour colour =
+                std::isupper(symbol) ? Colour::White : Colour::Black;
+
+            Piece piece = c2p[std::tolower(symbol)];
+            board->squares[rank * 8 + file] = colour | piece;
+            file++;
+        }
+    }
+    return board;
+}
+
+std::string Board::to_fen() {
+    std::map<int, char> p2c{
+        {Piece::King, 'k'},
+        {Piece::Pawn, 'p'},
+        {Piece::Knigt, 'n'},
+        {Piece::Bishop, 'b'},
+        {Piece::Rook, 'r'},
+        {Piece::Queen, 'q'},
+    };
+
+    std::string ret;
+    for (int rank = 7; rank >= 0; rank--) {
+        int empty_cell_counter = 0;
+        for (int file = 0; file < 8; file++) {
+            if (this->squares[rank * 8 + file] == Piece::None) {
+                empty_cell_counter++;
+                continue;
+            }
+
+            int full_piece = this->squares[rank * 8 + file];
+            char piece = p2c[full_piece & 0b111];
+            Colour colour = (full_piece & 0b11000) == Colour::White
+                              ? Colour::White
+                              : Colour::Black;
+
+            if (empty_cell_counter > 0) {
+                ret += std::to_string(empty_cell_counter);
+                empty_cell_counter = 0;
+            }
+            ret += colour == Colour::White ? std::toupper(piece) : piece;
+        }
+        if (empty_cell_counter > 0)
+            ret += std::to_string(empty_cell_counter);
+        if (rank > 0)
+            ret += "/";
+    }
+    return ret;
+}

cpp/src/board.hpp

@@ -0,0 +1,22 @@
+#pragma once
+
+#include "piece.hpp"
+
+#include <string>
+
+enum CastleRights {
+    KingSide = 1,
+    QueenSide = 2,
+};
+
+class Board {
+  private:
+    int8_t squares[64] = {Piece::None};
+    Colour turn;
+    int8_t castle_rights;
+
+  public:
+    static Board* setup_fen_position(std::string fen);
+
+    std::string to_fen();
+};

cpp/src/main.cpp

@@ -0,0 +1,22 @@
+#include "board.hpp"
+
+#include <iostream>
+
+int main(int argc, char* argv[]) {
+    std::string pos =
+        "rnbq1k1r/pp1Pbppp/2p5/8/2B5/8/PPP1NnPP/RNBQK2R w KQ - 1 8";
+    Board* b = Board::setup_fen_position(pos);
+
+    std::cout << sizeof(Board) << std::endl;
+    std::cout << sizeof(int8_t[64]) << std::endl;
+    std::cout << sizeof(Colour) << std::endl;
+
+    std::string fen = b->to_fen();
+
+    std::cout << pos << std::endl;
+    std::cout << fen << std::endl;
+
+    std::cout << (fen.substr(0, fen.find(" ")) == pos.substr(0, pos.find(" ")))
+              << std::endl;
+    return 0;
+}

cpp/src/piece.hpp

@@ -0,0 +1,14 @@
+enum Piece {
+    None = 0,
+    King = 1,
+    Pawn = 2,
+    Knigt = 3,
+    Bishop = 4,
+    Rook = 5,
+    Queen = 6,
+};
+
+enum Colour {
+    White = 8,
+    Black = 16,
+};