A Modern C++ Chess Library

chesscxx is a C++23 library for chess programming. It provides the essential tools for working with chess: simulating games, generating legal moves, parsing, and formatting.

Features

• Game simulation — Create and manage chess games, apply validated moves, and query game state.

• Parsing — Read moves (SAN, UCI), positions (FEN), and games (PGN).

• Formatting — Convert moves, positions, and games to multiple string formats.

• Move generation — Generate all legal moves for any position.

• Documentation — Comprehensive API reference with examples. See the docs →

• Quality assurance — Tested and validated to ensure correctness and reliability.

Benchmarks

Perft

The following results were obtained by running perft benchmarks on (4 X 3241.88 MHz CPU s), measured with Google Benchmark.

FEN	Depth	Time (ms)
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1	4	198213
r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 1	3	135330
8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - - 0 1	4	22685
r3k2r/Pppp1ppp/1b3nbN/nP6/BBP1P3/q4N2/Pp1P2PP/R2Q1RK1 w kq - 0 1	4	460994
rnbq1k1r/pp1Pbppp/2p5/8/2B5/8/PPP1NnPP/RNBQK2R w KQ - 1 8	3	62382
r4rk1/1pp1qppp/p1np1n2/2b1p1B1/2B1P1b1/P1NP1N2/1PP1QPPP/R4RK1 w - - 0 10	3	91085

Compiler Compatibility

Compiler	Minimum Version
GCC (libstdc++)	15.1

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For more details, explore the sections below:

• Getting Started
• API Reference
• Contributing to chesscxx
• License