Never assume clang flags based on the version

CMakeLists.txt

@@ -254,7 +254,8 @@ set_default_db_backend(${DATABASE_BACKEND})
 if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_C_COMPILER MATCHES "icc" OR (CMAKE_CXX_COMPILER_ID MATCHES "Clang"))
     set(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS} -Wno-long-long -std=iso9899:1990 -Wundef -Wcast-align -Werror-implicit-function-declaration -Wchar-subscripts -Wall -Wextra -Wpointer-arith -Wwrite-strings -Wformat-security -Wmissing-format-attribute -fno-common")
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wnon-virtual-dtor -Wundef -Wcast-align -Wchar-subscripts -Wall -Wextra -Wpointer-arith -Wformat-security -fno-common -pedantic")
-    if ((CMAKE_CXX_COMPILER_ID MATCHES "Clang") AND (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 10))
+    CHECK_CXX_COMPILER_FLAG(-Wno-deprecated-copy NO_DEPRECATED_COPY)
+    if (NO_DEPRECATED_COPY)
         set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-deprecated-copy")
     endif()