update demo to include an external library dependency (eg, google re2)

.github/workflows/pip.yml

@@ -45,6 +45,30 @@ jobs:
         echo "DISTUTILS_USE_SDK=1" >> $GITHUB_ENV
         echo "MSSdk=1" >> $GITHUB_ENV
 
+    - name: Update vcpkg
+      run: |
+        cd C:\vcpkg
+        git pull
+        .\\bootstrap-vcpkg.bat
+      if: startsWith(matrix.os, 'win')
+
+    - name: Install library deps with vcpkg
+      run: |
+        vcpkg install eigen3:x64-windows
+        vcpkg integrate install
+      if: startsWith(matrix.os, 'win')
+
+    - name: Install library deps with brew
+      run: |
+        brew install -s eigen
+      if: startsWith(matrix.os, 'mac')
+
+    - name: Install library deps with apt
+      if: runner.os == 'Linux'           
+      run: |
+        sudo apt-get -qq update
+        sudo apt-get install -y libeigen3-dev
+
     - name: Build and install
       run: pip install --verbose .
 

.github/workflows/wheels.yml

@@ -54,6 +54,11 @@ jobs:
 
     - uses: actions/setup-python@v2
 
+    - name: Install library deps with apt
+      run: |
+	sudo apt-get -qq update
+        sudo apt-get install -y libeigen3-dev
+
     - name: Install cibuildwheel
       run: python -m pip install cibuildwheel==1.6.3
 

CMakeLists.txt

@@ -1,9 +1,19 @@
 cmake_minimum_required(VERSION 3.4...3.18)
 project(cmake_example)
 
+find_package(Eigen3 CONFIG REQUIRED)
+find_package(Threads REQUIRED)
+
 add_subdirectory(pybind11)
 pybind11_add_module(cmake_example src/main.cpp)
 
+set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
 # EXAMPLE_VERSION_INFO is defined by setup.py and passed into the C++ code as a
 # define (VERSION_INFO) here.
 target_compile_definitions(cmake_example PRIVATE VERSION_INFO=${EXAMPLE_VERSION_INFO})
+
+target_compile_features(cmake_example INTERFACE cxx_std_11)
+target_link_libraries(cmake_example PRIVATE Eigen3::Eigen)

tox.ini

@@ -0,0 +1,33 @@
+[tox]
+envlist = py3{6,7,8,9}
+skip_missing_interpreters = true
+
+[tox:travis]
+3.6 = py36
+3.7 = py37
+3.8 = py38
+3.9 = py39
+
+[testenv]
+passenv = CI PYTHON CC CXX
+
+deps =
+    pip>=19.0.1
+    wheel
+
+commands =
+    pip install .
+    python tests/test.py
+    #py.test . --cov --cov-report term-missing
+    # codecov
+
+[testenv:deploy]
+passenv = CI PYTHON CC CXX
+
+deps =
+    pip>=19.0.1
+    wheel
+
+commands =
+    python setup.py sdist
+    python setup.py bdist_wheel