g++ (4.7.2) bug or feature, when initializing static arrays at compile-time?

Okay, so I was trying to do something clever by initializing a bunch of `constexpr static int const` arrays at compile-time. Even though the runtime-performance is not at all governed by initializing these arrays, it seemed like a fun little exercise. I wrote a test-setup to see if it was possible, and I ended up being able to do this: ``` struct Test { constexpr static int const array[10] = Array<int, 10, 0, Increment>::array; }; constexpr int const Test::array[10]; int main() { cout << Test::array[3] << '\n'; } ``` Here, `Array` has a static member called `array` which contains 10 `int`s, starting at 0, where the value of each subsequent element is determined by a Template-Metaprogramming functor called `Increment` (i.e. `{0, 1, ..., 9}`). As expected, the program prints out the number `3`. Awesome, right? I can just write functors now and initialize arrays will all kinds of funky patterns at compile-time. Next step: un-hardcode the array-size 10 by making `Test` a class-template like so: ``` template <size_t Size> struct Test { constexpr static int const array[Size] = Array<int, Size, 0, Increment>::array; }; template <size_t Size> constexpr int const Test<Size>::array[Size]; int main() { cout << Test<10>::array[3] << '\n'; } ``` However, all of a sudden it doesn't compile anymore with the message: ``` test.cc:43:72: error: array must be initialized with a brace-enclosed initializer ``` Why does this happen? Is there a reason that this kind of initialization has become invalid once I turn the class into a class-template, or have I stumbled upon something unimplemented/buggy in GCC? FYI, I can post the rest of my code (the implementation of `Array` for example) on request. For now I think this should be enough. EDIT The error can be reproduced with a different, trivial, implementation of `Array` to save some space here: ``` template <size_t Size> struct Array { constexpr static int const array[Size] = {}; }; template <size_t Size> struct Test { constexpr static int const array[Size] = Array<Size>::array; }; ```