Define HB_MARK_AS_FLAG_T as a macro instead of using templates The generic template operator overloading was causing more problems than it solved. Eg: https://github.com/behdad/harfbuzz/pull/163 https://github.com/behdad/harfbuzz/issues/175 So, just use macros. Fixes https://github.com/behdad/harfbuzz/issues/175 Fixes https://github.com/behdad/harfbuzz/pull/178