The following program returns 1 instead of 0 because gcc seems not to do a static_cast followed by a const_cast when doing the C-style cast. This is in violation of 5.4 of the standard.
The problem first appeared in gcc 4.0.0. Here is the -v output of the version I am currently using: Target: i486-linux-gnu Configured with: ../src/configure -v --enable-languages=c,c++,java,f95,objc,ada,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --enable-nls --without-included-gettext --enable-threads=posix --program-suffix=-4.0 --enable-__cxa_atexit --enable-libstdcxx-allocator=mt --enable-clocale=gnu --enable-libstdcxx-debug --enable-java-gc=boehm --enable-java-awt=gtk --with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --enable-mpfr --disable-werror --enable-checking=release i486-linux-gnu Thread model: posix gcc version 4.0.1 20050617 (prerelease) (Debian 4.0.0-10) ----------------------------------------------------------------------------- struct A { int a; }; struct B { int b; }; struct C: public A, public B { }; int main() { C c; const C *cptr = &c; B* bad = (B*)cptr; B* good = const_cast<B*>(static_cast<const B *>(cptr)); return bad != good; } -- Summary: C-Style cast does reinterpret_cast when it should do a static_cast Product: gcc Version: 4.0.0 Status: UNCONFIRMED Severity: normal Priority: P2 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: gccbug at gammarayburst dot de CC: gcc-bugs at gcc dot gnu dot org GCC build triplet: i486-linux-gnu GCC host triplet: i686-linux-gnu GCC target triplet: i486-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22281