Disable deprecation warning, to silence some harmless BGL-related warnings

configure.ac

@@ -50,9 +50,11 @@ AC_ARG_ENABLE([debug], [AS_HELP_STRING([--enable-debug@<:@=full@:>@],[compile de
         )
 
 dnl set template depth and hidden visibility
-
 [CXXFLAGS="${CXXFLAGS} -ftemplate-depth-150"]
 
+dnl disable deprecation warning, to silence some harmless BGL-related warnings
+[CXXFLAGS="${CXXFLAGS} -Wno-deprecated"]
+
 AC_MSG_CHECKING(whether to enable function inlining...)
 
 AC_ARG_ENABLE([inline], [AS_HELP_STRING([--disable-inline],[disable inline functions [default=enabled] ])],