Add CMakeLists.txt at project root; find SFG, specify interface target and include dirs there.

CMakeLists.txt

+
+SET ( CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_CURRENT_SOURCE_DIR}/cmake )
+find_package( PystencilsSfg REQUIRED )
+
+add_subdirectory( include )

cmake/FindPystencilsSfg.cmake

+set( PystencilsSfg_FOUND OFF CACHE BOOL "pystencils source file generator found" )
+
+mark_as_advanced( PystencilsSfg_FOUND )
+
+find_package( Python COMPONENTS Interpreter REQUIRED )
+
+#   Try to find pystencils-sfg in the python environment
+
+execute_process(COMMAND ${Python_EXECUTABLE} -m pystencilssfg version --no-newline
+                RESULT_VARIABLE _PystencilsSfgFindResult OUTPUT_VARIABLE PystencilsSfg_VERSION )
+
+if(${_PystencilsSfgFindResult} EQUAL 0)
+    set( PystencilsSfg_FOUND ON )
+endif()
+
+if(DEFINED PystencilsSfg_FIND_REQUIRED)
+    if(NOT ${PystencilsSfg_FOUND})
+        message( FATAL_ERROR "Could not find pystencils-sfg in current Python environment." )
+    endif()
+endif()
+
+if(${PystencilsSfg_FOUND})
+    message( STATUS "Found pystencils Source File Generator (Version ${PystencilsSfg_VERSION})")
+    
+    execute_process(COMMAND ${Python_EXECUTABLE} -m pystencilssfg cmake modulepath --no-newline
+                    OUTPUT_VARIABLE _PystencilsSfg_CMAKE_MODULE_PATH)
+
+    set( CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${_PystencilsSfg_CMAKE_MODULE_PATH})
+    include( PystencilsSfg )
+endif()
+

include/CMakeLists.txt

@@ -2,9 +2,11 @@
 add_library( sfg_walberla INTERFACE )
 
 target_sources( sfg_walberla
-    INTERFACE GenericHbbBoundary.hpp GenericHbbBoundary.ipp
+    INTERFACE GenericHbbBoundary.hpp
 )
 
+target_include_directories( sfg_walberla INTERFACE ${CMAKE_CURRENT_SOURCE_DIR} )
+
 target_link_libraries(
     sfg_walberla
     INTERFACE

include/GenericHbbBoundary.hpp

@@ -124,5 +124,3 @@ void GenericHbbBoundary< Stencil_T >::fillFromFlagField(IBlock& block, ConstBloc
 
 } // namespace sfg
 } // namespace walberla
-
-#include "GenericHbbBoundary.ipp"

include/GenericHbbBoundary.ipp

-#pragma once