"Expression result unused" build failure(s) — clang 3.5.0

clang triggers a warning on this useless usage of the define. The -Werror causes the failure.
#define bar(int) (1)

void foo() {
    bar(2);
}

With gcc, this warning is only displayed with -Wall.
PackageVersionSupposed error messageFull log Bug report
libshevek 1.4-1src/iostring.hh:728:3: error: expression result unused; should this cast be to 'void'? [-Werror,-Wunused-value] Log 754323

1 errors