Changing inherited headers

Setting spdlog header inheritance in system mod to avoid that more drastic warnings policies raise warning in project including spdlog.

CMakeLists.txt

@@ -143,8 +143,10 @@ endif()
 add_library(spdlog::spdlog ALIAS spdlog)
 
 target_compile_definitions(spdlog PUBLIC SPDLOG_COMPILED_LIB)
-target_include_directories(spdlog PUBLIC "$<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/include>"
-                                         "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
+target_include_directories(spdlog PRIVATE "$<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/include>"
+                                          "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
+target_include_directories(spdlog SYSTEM INTERFACE "$<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/include>"
+                                                   "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
 target_link_libraries(spdlog PUBLIC Threads::Threads)
 spdlog_enable_warnings(spdlog)
 
@@ -162,8 +164,8 @@ endif()
 add_library(spdlog_header_only INTERFACE)
 add_library(spdlog::spdlog_header_only ALIAS spdlog_header_only)
 
-target_include_directories(spdlog_header_only INTERFACE "$<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/include>"
-                                                        "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
+target_include_directories(spdlog_header_only SYSTEM INTERFACE "$<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/include>"
+                                                               "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
 target_link_libraries(spdlog_header_only INTERFACE Threads::Threads)
 
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