[cfe-dev] C++: Reference to member in sizeof expression of another member declaration

[Florian Weimer]

clang++ (trunk, both C++03 and C++11 modes) rejects the following program:

union u {
   int a;
   char b[sizeof(a)];
};

t.cpp:3:17: error: invalid use of non-static data member 'a'
   char b[sizeof(a)];
                 ^

This seems valid C++, considering this language in [expr.prim.general]: 
"An id-expression that denotes a non-static data member […] can only be 
used […] if that id-expression […] appears in an unevaluated operand"

-- 
Florian Weimer / Red Hat Product Security Team