Decouple demo from top-level cmake

README.md

@@ -14,3 +14,14 @@ make
 ctest
 make install
 ```
+
+Usage is demonstrated in directory demo/. To build and run example
+code that prints q vs |F(q)| for some sequences of q vectors, do
+```
+cd demo
+mkdir build
+cd build
+cmake ..
+make
+octahedron
+```
\ No newline at end of file

demo/CMakeLists.txt

+cmake_minimum_required(VERSION 3.15 FATAL_ERROR)
+
+project(demo_using_formfactor VERSION 0.1.2 LANGUAGES CXX)
+
+## Compiler settings.
+option(WERROR "Treat warnings as errors" OFF)
+
+set(CMAKE_CXX_STANDARD 17)
+if(WIN32)
+    set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
+    message(STATUS "compiling for Windows")
+else()
+    option(PEDANTIC "Compile with pedantic warnings" ON)
+    if(PEDANTIC)
+        add_compile_options(-pedantic -Wall)
+    endif()
+endif()
+add_compile_options(-O2)
+if(WERROR)
+    add_compile_options(-Werror)
+endif()
+
+## Dependencies
+find_package(LibHeinz REQUIRED CONFIG)
+find_package(formfactor REQUIRED CONFIG)
+
+## Source
 set(demos
     octahedron
     )
 
+## Configure executable
 foreach(app ${demos})
     add_executable(${app} ${app}.cpp)
-#    target_include_directories(${app} PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
     target_link_libraries(${app} formfactor)
 endforeach()