C++ zig build demo

This demo shows how to use build.zig to compile a C++ project and call C++ lib function in Zig. It includes everything you need to know about when dealing with a C++ project with Zig.

It's worth it to point out that @cImport and @cInclude only works for C headers, it doesn't work for C++ header, that's why you have to write a wrapper header file if you want to include a C++ lib header file!

src/utils/a.h and src/utils/b.h mix the C++ and wapper in the same header file, that's why it works.

The project has the following folder structure:

.
├── README.md
├── build               #`cmake` build folder
├── build.zig           # `Zig` build configuration file
├── CMakeLists.txt      # `cmake` configuration file
├── configure.sh        # Configure `cmake`
├── run.sh              # Build `main.cpp` with `cmake` and run
├── build_cpp.sh        # Build `main.cpp` with `clang++`
├── build_c.sh          # Build `main.c` with `clang`
└── src
     ├── main.cpp       # `C++` calls namespace functions in `liba.so` and `lib.so`
     ├── main.c         # `C` calls namespace functions in `liba.so` and `lib.so`
     ├── main.zig       # `Zig` calls namespace functions in `liba.so` and `lib.so`
     └── utils          # Lib `a` and `b`
         ├── a.cpp
         ├── a.h
         ├── b.cpp
         └── b.h

Use cmake to build and run

cmake builds the build/liba.so and build/lib.so first, then builds the ./build/cpp and links it to the build/liba.so and build/libb.so.

./configure.sh

./run.sh
# >>> Simple zig build CPP demo.
# >>> [ A - Result ] {
# {
#          invisible_value: 28
#          is_success: true
# }
# >>> A::Result destroyed.
# >>> [ B - Result ]
# {
#          invisible_float: 88.456
# }
# >>> B::Result destroye

Use clang++ to build and run

This only works once you build the project via cmake, as it doesn't build liba.so and lib.so but just links to them!!!

./build_cpp.sh && LD_LIBRARY_PATH=./build ./build/cpp_2
# >>> Simple zig build CPP demo.
# >>> [ A - Result ] {
# {
#          invisible_value: 28
#          is_success: true
# }
# >>> A::Result destroyed.
# >>> [ B - Result ]
# {
#          invisible_float: 88.456
# }
# >>> B::Result destroye

Call C++ lib function in C

This only works once you build the project via cmake, as it doesn't build liba.so and lib.so but just links to them!!!

 ./build_c.sh && LD_LIBRARY_PATH=./build build/c

# >>> Calling C++ lib function in C:)
#
# >>> a_result value: 38
# >>> a_result is_success: true
# >>> [ A - Result ] {
# {
#          invisible_value: 38
#          is_success: true
# }
# >>> A::Result destroyed.
#
# >>> b_result value: 123.789
# >>> [ B - Result ]
# {
#          invisible_float: 123.789
# }
# >>> B::Result destroyed.

Use zig to build the project

This only works once you build the project via cmake, as it doesn't build liba.so and lib.so but just links to them!!!

• Build and run C++ binary (zig-out/bin/cpp_binary)

  zig build run-cpp
  
  # >>> Simple zig build CPP demo.
  # >>> [ A - Result ] {
  # {
  #          invisible_value: 28
  #          is_success: true
  # }
  # >>> A::Result destroyed.
  # >>> [ B - Result ]
  # {
  #          invisible_float: 88.456
  # }
  # >>> B::Result destroyed.

  
  

• Build and run zig binary (zig-out/bin/zig_binary)

  zig build run-zig
  
  # >>> Calling C++ lib function in Zig:)
  #
  # >>> a_result value: 999
  # >>> a_result is_success: true
  # >>> [ A - Result ] {
  # {
  #          invisible_value: 999
  #          is_success: true
  # }
  # >>> A::Result destroyed.
  #
  # >>> b_result value: 55.456>>> [ B - Result ]
  # {
  #          invisible_float: 55.456
  # }
  # >>> B::Result destroyed.