C/xx Swift Package Interop

This is an example package demonstrating how to use the C and C++ interoperability in Swift Package.

Project Structure

.
├── MathUtils.swift
│   ├── Package.swift
│   ├── Sources
│   │   ├── ExternalMathUtilsC
│   │   │   ├── include
│   │   │   │   └── math_utils.h
│   │   │   ├── lib
│   │   │   │   └── libmath_utils.a
│   │   │   ├── math_utils.pk
│   │   │   └── module.modulemap
│   │   ├── ExternalMathUtilsCxx
│   │   │   ├── include
│   │   │   │   └── complex_math.h
│   │   │   ├── lib
│   │   │   │   └── libcomplexmath.a
│   │   │   └── module.modulemap
│   │   ├── MathUtils
│   │   │   └── MathUtils.swift
│   │   ├── MathUtilsC
│   │   │   ├── cipher_kit.c
│   │   │   └── include
│   │   │       ├── cipher_kit.h
│   │   │       └── module.modulemap
│   │   ├── MathUtilsCxx
│   │   │   ├── include
│   │   │   │   ├── MathUtilsCxx.hpp
│   │   │   │   └── module.modulemap
│   │   │   └── MathUtilsCxx.cpp
│   │   └── MathUtilsExecutable
│   │       └── MathUtilsExecutable.swift
│   └── Tests
│       └── MathUtilsTests
│           └── MathUtilsTests.swift
├── MathUtilsC
│   ├── Makefile
│   ├── math_utils.c
│   ├── math_utils.h
├── MathUtilsCxx
│   ├── complex_math.cpp
│   ├── complex_math.h
│   └── Makefile
└── README.md

The /MathUtilsC and /MathUtilsCxx are just simple c library and c++ library that can be compiled using the companion Makefiles.

The MathUtils.swift is a swift package that references the two compiled static library above, in /MathUtils.swift/Sources/ExternalMathUtilsC and /MathUtils.swift/Sources/ExternalMathUtilsCxx, and contains a c++ target using the ExternalMathUtilsC`` and a swift target all three c/++ libraries. It also provides an executable MathUtilsExecutable` that outputs the results by calling the swift target which uses the c and c++ library under the hood.

Note that extern "C" is needed for the c headers in /MathUtils.swift/Sources/ExternalMathUtilsC (see here).

Run The Sample Executable

cd MathUtils.swift
swift run