Static initializing a struct of unions of arrays - c++

Question

I am trying to write static initializers for this class:
class Cube3x3
{
union CornerData
{
u8 mData8[8];
u32 mData16[4];
u32 mData32[2];
u64 mData64;
};
union EdgeData
{
u8 mData8[12];
u32 mData32[3];
};
CornerData mCorners;
EdgeData mEdges;
static const Cube3x3 sSolved;
};
I've tried this, and a lot of variants, and it seems like nothing I try will work.
const Cube3x3 Cube3x3::sSolved =
{
{ 0, 0, 1, 0, 0, 0, 1, 0 },
{ 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0 }
};
Does anyone know how, or if, its possible to static initialize this?

Answer 1

If you are willing to change Cube3x3 from a class to a struct, you can use:
const Cube3x3 Cube3x3::sSolved = {0};
Update
When a struct is used, you can also initialize the members with non-zero values, like you have in the updated question.
const Cube3x3 Cube3x3::sSolved =
{
{ 0, 0, 1, 0, 0, 0, 1, 0 },
{ 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0 }
};

Answer 2

One solution is to use C++11 lambdas to initialize it.
const Cube3x3 Cube3x3::sSolved = []{
Cube3x3 cube;
std::fill(std::begin(cube.mCorners.mData8), std::end(cube.mCorners.mData8), 0);
std::fill(std::begin(cube.mEdges.mData8), std::end(cube.mEdges.mData8), 0);
return cube;
}();
Live Example
Note the () at the end, which indicates that we are calling that lambda function. If you are using a non-C++11 compiler, or at least one that doesn't yet support C++11 lambdas, you could write a function with basically the same body as you would have when writing a lambda. You then need to call that function when static-initializing the desired object.
Cube3x3 initialize() {
Cube3x3 cube;
std::fill(&cube.mCorners.mData8[0], &cube.mCorners.mData8[8], 0);
std::fill(&cube.mEdges.mData8[0], &cube.mEdges.mData8[8], 0);
return cube;
}
const Cube3x3 Cube3x3::sSolved = initialize();
Live Example

Answer 3

The code is working for me if I add a constructor for your class that takes the CornerData and EdgeData as arguments.
Cube3x3(CornerData cornerData, EdgeData edgeData)
: mCorners(cornerData),
mEdges(edgeData)
{
}
Here is the link: http://ideone.com/XzBXZM