C++11 Code::Blocks GCC crashes when compiling variadic template of dependent member structs

Question

I was testing an idea with variadic templates in C++ using Code::Blocks, and when I try to compile it, the build fails and says:

'
in dependent_type_p, at cp/pt.c:19367
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://tdm-gcc.tdragon.net/bugs> for instructions.
Process terminated with status 1 (0 minute(s), 1 second(s))
0 error(s), 0 warning(s) (0 minute(s), 1 second(s))

I followed the instructions and submitted a bug report, but in the meantime I want to know if I need to fix my code or get a new compiler. The code I wrote is:

#include <iostream>
#include <array>
using namespace std;

struct Foo1
{
    struct init {};
};

struct Foo2 : public Foo1
{
    struct init{};
};

struct Foo3 : public Foo2
{
    struct init{};
};

template <typename... Args>
void Bar(typename Args::init... args)
{
    array<void*, sizeof...(Args) + 2> t = {nullptr, &args..., nullptr};
    for (size_t x = 1; x < sizeof...(Args) + 1; ++x)
        cout << t[x] << endl;
}

int main()
{
    Foo1::init a;
    Foo2::init b;
    Foo3::init c;
    Bar<Foo1, Foo2, Foo3>(a, b, c);
}

It works if I manually expand Bar to:

template <typename A, typename B, typename C>
void Bar(typename A::init a, typename B::init b, typename C::init c)
{
    array<void*, 5> t = {nullptr, &a, &b, &c, nullptr};
    for (size_t x = 1; x < 4; ++x)
        cout << t[x] << endl;
}

The error is somehow caused by the variadic template, but I don't understand it at all. I was hesitant to ask because we are supposed to specify the exact problem, but all the compiler said was something about a dependent type.

Answer 1

This is an (apparently unreported) bug in GCC 4.7 (the code causes GCC 4.5 and 4.6 to ICE too, but in a different and even more hilarious way, namely Internal compiler error: Error reporting routines re-entered.).

If anyone else hits this -- just upgrade to GCC 4.8 or newer, where it has been fixed.