(Sorry, pressed return to early...)

g++ accepts the following code, which contains a typedef that's supposed to act as a static assert. 
-------------------------------------------------------------------------------
template<int N>
struct Test
{
    Test()
    {
        typedef struct StaticAssert {unsigned condition : (N); } XXX;
    }
};

int
main()
{
    Test<0> T;
}
-------------------------------------------------------------------------------

Confirmed. The typedef is only rejected if it is actually used to define
a variable.

W.

Also fixed for 4.8.0. I'm adding the test and closing the PR.

Done.