Build Matrix

OS / Compiler	GCC 13	GCC 14	GCC 15	Clang 17	Clang 18	Clang 19	Clang 20
Ubuntu 22.04
Ubuntu 24.04

libdecimal — Deterministic Decimal Arithmetic Built on Intel LIBBID

libdecimal is a header-only, production-grade decimal arithmetic library built for systems where correctness is not negotiable. If your P&L depends on the last digit — you’re in the right place. If your connectivity stack (e.g. Interactive Brokers) already relies on Intel LIBBID — this fits naturally. This is not a “numeric playground” — it’s infrastructure. For

• trading engines
• risk systems
• settlement pipelines
• cryptographic finance primitives

Why This Exists

• Intel LIBBID is already in your stack — but the API is painful
• The build system failed for you, we had it covered
• Clean, modern C++ layer over LIBBID (no wrapper spaghetti)
• Exact BID binary representation for interop & persistence
• You are looking for an alternative to Boost.Decimal

You get:

• Exact base-10 semantics
• Deterministic cross-platform results
• Zero rounding surprises
• Precision suitable for financial systems
• Compile-time friendly (constexpr where it matters)
• Clean integration with modern C++ (C++20/23)

Who This Is For

This is for engineers who:

• know why IEEE754 is insufficient for finance
• have debugged rounding errors at 3am
• care about reproducibility under audit
• build systems where mistakes cost real money

If you’re building:

• low-latency trading infra
• accounting engines
• blockchain / DeFi protocols
• risk or pricing systems

Development

cmake -DCMAKE_BUILD_TYPE=Debug -Dlibdecimal_BUILD_TESTS=ON -S . -B build # configure (debug + tests)
cmake --build build --parallel                                           # build everything
cd build && ctest --output-on-failure                                    # run tests
cmake --build build --target docs_build                                  # install mkdocs locally
cmake --build build --target docs_serve                                  # run webserver @ http://127.0.0.1:9000/

Installation

sudo apt install build-essential cmake
cmake -DCMAKE_BUILD_TYPE=Release -S . -B build
cmake --build build --parallel
sudo cmake --install build

Usage

After installation, libdecimal is available as a standard CMake package:

find_package(libdecimal REQUIRED)
add_executable(app main.cpp)
target_link_libraries(app PRIVATE libdecimal::libdecimal)

Attribution

LIBDECIMAL builds on Intel’s LIBBID implementation of IEEE 754 decimal arithmetic. The heavy lifting — the arithmetic itself — comes from the work of Marius Cornea, John Harrison, Cristina Anderson, and Evgeny Gvozdev. The underlying model traces back to Mike Cowlishaw and the IEEE 754 standard.

The template/macro contraption that makes it usable in modern C++, along with the full decomposition of BID into sign, significand, and exponent — that is on me.