gistfile1.txt

struct Bar
{
   Bar();
   Bar(int);
};

struct Meow
{
   Meow(int a, Bar b);
};

struct Foo
{
   Bar b;
   Meow m;
   unsigned u;
};

Meow test_meow()
{
   return {10, {}};
}

Foo test()
{
   return {10, {10, {}}, 0};
}

// G++ 4.7.1 compiles fine.
// Clang++ 3.1:
// test2.cpp:21:16: error: initialization of non-aggregate type 'Meow' with an
//       initializer list
//    return {10, {10, {}}, 0};
//                ^~~~~~~~
// 1 error generated.