CMakeLists.txt

CMAKE_MINIMUM_REQUIRED(VERSION 3.0.2 FATAL_ERROR)

PROJECT(core VERSION 0.0.1 LANGUAGES CXX)

# Sets up some sane compiler flags for C++14 with appropriate warnings;
# tested to work with GCC 4.9+ and Clang 3.6+ --- feel free to modify

IF(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14 -Wall -Wextra -pedantic -Wold-style-cast -Wuninitialized -Wunreachable-code -Wstrict-overflow=3 -D_FORTIFY_SOURCE=2 -ffunction-sections -fdata-sections")
  SET(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-O1 -Wl,--hash-style=gnu -Wl,--sort-common -Wl,--gc-sections")
  IF(${CMAKE_CXX_COMPILER_ID} MATCHES "GNU")
    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fmax-errors=1")
    IF (${CMAKE_BUILD_TYPE} MATCHES "Debug")
      SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Og -ggdb3 -fno-omit-frame-pointer")
    ENDIF()
  ELSEIF(${CMAKE_CXX_COMPILER_ID} MATCHES "Clang")
    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -ferror-limit=1")
    IF (${CMAKE_BUILD_TYPE} MATCHES "Debug")
      SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-omit-frame-pointer")
    ENDIF()
  ENDIF()
ELSE()
  MESSAGE(FATAL_ERROR "Unsupported system")
ENDIF()

FIND_PACKAGE(Threads REQUIRED)
FIND_PACKAGE(PythonLibs 2.7 REQUIRED)
FIND_PACKAGE(Boost 1.59.0 REQUIRED COMPONENTS filesystem system program_options thread timer log log_setup unit_test_framework python)
ADD_DEFINITIONS(-DBOOST_ALL_DYN_LINK)
ADD_DEFINITIONS(-DBOOST_FILESYSTEM_NO_DEPRECATED)


# Optional: you can make it more modular by putting the following into
#           subdir/CMakeLists.txt and ADD_SUBDIRECTORY(subdir) here


# By default Python searches for module.so when doing import module
# force .so on OSX instead of .dylib
IF(APPLE)
  SET(CMAKE_SHARED_LIBRARY_SUFFIX ".so")
ENDIF()

ADD_LIBRARY(core SHARED "core.cc")
TARGET_LINK_LIBRARIES(core ${Boost_LIBRARIES} ${PYTHON_LIBRARIES})
TARGET_INCLUDE_DIRECTORIES(core SYSTEM PUBLIC ${Boost_INCLUDE_DIRS} ${PYTHON_INCLUDE_DIRS})

# By default CMake prefixes shared libraries with lib; we would get
# libmodule but want module in order to be able to do import module
SET_TARGET_PROPERTIES(core PROPERTIES PREFIX "")

# Optional install target
INSTALL(TARGETS core DESTINATION lib)

core.cc

#include <boost/python.hpp>

#include <string>

struct Dummy {
  std::string s;
  void fn() {}
};

BOOST_PYTHON_MODULE(core) {
  using namespace boost::python;

  class_<Dummy>("Dummy")                //
      .def_readwrite("str", &Dummy::s)  //
      .def("fun", &Dummy::fn);
}

example.md

Build core.so Python module

mkdir build
pushd build
cmake .. -DCMAKE_BUILD_TYPE=Release
cmake --build .

Look, it's there

file core.so

Let's try to use it (make sure to start the interpreter for the Python version you linked against above)

python2
>>> from core import Dummy
>>> x = Dummy()
>>> x.fun()
>>> x.str = "Hello"
>>> print(x.str)
Hello

Cool!