public:

VisibleInnerIterable();

typedef std::vector<int> Iterable;

const Iterable& getIterable();

private:

Iterable iterable;

// VisibleInnerIterable

{

VisibleInnerIterable c;

VisibleInnerIterable::Iterable ita = c.getIterable();

VisibleInnerIterable::Iterable::iterator it = ita.begin();

int i;

int is[]{0,1,2};

for (

it = ita.begin(), i=0;

it != ita.end();

++it, ++i

)

{

assert(*it == is[i]);

}

}

/*

{

// Given width and height.

{

int width = 2, height = 3;

std::vector<std::vector<int>> array_2d(height, std::vector<int>(width));

array_2d[0][0] = 1;

array_2d[2][1] = 5;

assert(array_2d[0][0] == 1);

assert(array_2d[0][1] == 0);

assert(array_2d[2][1] == 5);

}

// Uniform initialized.

{

std::vector<std::vector<int>> array_2d{

{0, 1},

{2, 3},

{4, 5},

};

assert(array_2d[0][0] == 0);

assert(array_2d[2][1] == 5);

}

}