toml++ `tomlplusplus/`

Type: TOML Parser Library
License: MIT
Fork Origin: GitHub
Status: Detached Fork (independently maintained)
Specification: TOML v1.0.0 Latest Version: 0.0.5-1

Overview

toml++ is a header-only TOML configuration file parser and serializer for C++17 and later. It provides a clean, intuitive API for reading and writing TOML files with full TOML v1.0.0 compliance.

ProjT Launcher maintains a detached fork for independent development and CI integration.

Usage in ProjT Launcher

toml++ is used for:

Configuration files — Reading launcher settings
Instance configs — Parsing instance metadata
Mod manifests — Processing fabric.mod.json alternatives
Pack metadata — Reading modpack configuration

Features

Feature	Status
TOML v1.0.0 compliant	✅
Header-only library	✅
C++17/20/23 support	✅
Unicode support	✅
Serialize to TOML	✅
Parse from string/file	✅
Error messages with line numbers	✅
Compile-time optimizations	✅

Quick Start

Single Header Include

#include <toml++/toml.hpp>

Parse TOML

// From string
auto config = toml::parse(R"(
    [server]
    host = "localhost"
    port = 8080
)");

// From file
auto config = toml::parse_file("config.toml");

// Access values
std::string host = config["server"]["host"].value_or("127.0.0.1");
int port = config["server"]["port"].value_or(80);

Create TOML

{% raw %}

auto tbl = toml::table{{
    {"server", toml::table{{
        {"host", "localhost"},
        {"port", 8080}
    }}}
}};

std::cout << tbl << std::endl;

{% endraw %}

Build Integration

CMake (Recommended)

toml++ is header-only, but provides a CMake target:

# Add as subdirectory
add_subdirectory(tomlplusplus)

# Or find installed package
find_package(tomlplusplus REQUIRED)

# Link to your target
target_link_libraries(your_target PRIVATE tomlplusplus::tomlplusplus)

Include Directly

target_include_directories(your_target PRIVATE path/to/tomlplusplus/include)

Compiler Requirements

Compiler	Minimum Version
GCC	8+
Clang	8+
MSVC	19.20+ (VS 2019)
ICC	19.11+

Configuration Options

Define before including to customize behavior:

// Disable exceptions
#define TOML_EXCEPTIONS 0

// Disable optional features
#define TOML_ENABLE_FORMATTERS 0
#define TOML_ENABLE_PARSER 0  // Write-only mode

// Unicode handling
#define TOML_ASSUME_UTF8_EVERYWHERE 1

Error Handling

With Exceptions (Default)

try {
    auto config = toml::parse_file("config.toml");
} catch (const toml::parse_error& err) {
    std::cerr << "Parse error at " << err.source().begin << ":\n"
              << err.description() << std::endl;
}

Without Exceptions

#define TOML_EXCEPTIONS 0

toml::parse_result result = toml::parse_file("config.toml");
if (!result) {
    std::cerr << "Parse error: " << result.error() << std::endl;
    return;
}
toml::table& config = result.table();

Testing

toml++ includes a comprehensive test suite:

cd tomlplusplus
mkdir build && cd build
cmake .. -DTOML_BUILD_TESTS=ON
cmake --build .
ctest -V

See ci-tomlplusplus.yml for CI configuration.

Documentation

Resource	Description
API Docs	Full API reference
TOML Spec	TOML v1.0.0 specification
Original README	Upstream library documentation
Website Build	Building API docs

Copyright & Licensing

Copyright (c) Mark Gillard <mark.gillard@outlook.com.au>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software to deal in the Software without restriction, including the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND.

Full license: tomlplusplus/LICENSE