CNL is a numerics library written in C++ which aims to do for int what the STL does for arrays. Its main roles are to help:

• approximate real numbers using fixed-point arithmetic;
• detect and prevent overflow and
• increase precision through alternative rounding modes.

A compositional design promotes seamless interoperability between numeric types. And by providing the thinnest wrappers over the widest range of numeric types, CNL aims to assist the development of:

• large-scale simulations including video games and scientific models;
• resource-constrained applications on embedded and mobile devices and
• math-intensive operations on specialized hardware such as GPUs and FPGAs.

The library's APIs are developed in colaboration with standardization bodies such as The C++ Standards Committee and members of The Khronos Group Inc. and it serves as a reference implementation for sections of the C++ Numbers Technical Specification. Please read proposals, P0037 and P0554 for more details.

Tested on Travis and CircleCI.

Requires:

• GCC 5.1 / Clang 3.5
• CMake (3.0.2)

Optional:

• Boost - facilitates multiprecision support
• Doxygen - generates documentation in the doc/gh-pages directory

Tested on AppVeyor and on Windows 10 Professional with CMake 3.8.0. Requires:

• MSBuild 15.0 (VS 2017)
• CMake 3.8.0

The library is hosted on GitHub:

cd /some/directory
git clone https://github.com/johnmcfarlane/cnl.git

CNL is a header-only library so there is no need to build it. However, it comes with a number of tests and benchmarks.

1. Generate the build system:

   cmake /some/directory/cnl

2. Build tests:

   • For Linux (in parallel using N cores):

     cmake --build . --target Tests -- -j N

   • For Windows:

     cmake --build . --target src/test/Tests

3. Run tests:

   ctest

1. Generate the build system (optimized):

   cmake -DCMAKE_BUILD_TYPE=Release /some/directory/cnl

2. Build benchmarks:

   cmake --build . --target Benchmark

3. Run benchmarks:

   src/benchmark/Benchmark

1. To describe CNL build options:

   cmake -LH /some/directory/cnl

2. Then to apply an option, e.g. to disabled exceptions:

   cmake -DEXCEPTIONS=OFF /some/directory/cnl

The API is exposed through headers in the include directory. Add this to your system header list and include, e.g.:

// to use a specific type:
#include <cnl/fixed_point.h>

// or to include all CNL types:
#include <cnl/all.h>

See example program, Tau, for more details.

• documentation
• Standard Library fixed-point proposal, P0037
• position paper illustrating the compositonal approach, P0554
• forum of Study Group 14

All feedback greatly appreciated.

• CNL Issues
• SG14 forum
• [email protected]

Developed with .