Try to install libsyclinterface/include/*.hpp files into separate folder

Author: oleksandr-pavlyk

libsyclinterface/CMakeLists.txt

@@ -1,7 +1,8 @@
-cmake_minimum_required(VERSION 3.10...3.22 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.21...3.22 FATAL_ERROR)
 
 project(
     "libDPCTLSYCLInterface"
+    LANGUAGES C CXX
     DESCRIPTION "A C API for a subset of SYCL"
 )
 
@@ -260,10 +261,12 @@ endif()
 # Install all headers
 
 file(GLOB MAIN_HEADERS "${CMAKE_CURRENT_SOURCE_DIR}/include/*.h")
-file(GLOB MAIN_HEADERS "${CMAKE_CURRENT_SOURCE_DIR}/include/*.hpp")
+file(GLOB MAIN_CXX_HEADERS "${CMAKE_CURRENT_SOURCE_DIR}/include/*.hpp")
 file(GLOB SUPPORT_HEADERS "${CMAKE_CURRENT_SOURCE_DIR}/include/Support/*.h")
 file(GLOB CONFIG_HEADERS "${CMAKE_CURRENT_SOURCE_DIR}/include/Config/*.h")
 
+message(STATUS "++++++++++ MAIN_CXX_HEADERS: ${MAIN_CXX_HEADERS}")
+
 set_target_properties(DPCTLSyclInterface
     PROPERTIES PUBLIC_HEADER
     "${MAIN_HEADERS}"
@@ -288,6 +291,10 @@ install(TARGETS
     PUBLIC_HEADER
     DESTINATION ${_include_destination}
 )
+install(
+    FILES ${MAIN_CXX_HEADERS}
+    DESTINATION ${_include_destination}/_cxx
+)
 install(
     FILES ${SUPPORT_HEADERS}
     DESTINATION ${_include_destination}/Support