CODEWITHSUNDEEP
c++visual-studio-2010data-structuresstl
Triumphant
Triumphant

Reputation: 958

How to define a 3d array with each dimension a different type in C++?

I want to define a 3D array like this:

Type ary[3/*enumeration type*/][6/*int*/][7/*const wchar**/];

Is it possible in C++? I'm using Visual Studio 2010, Boost library is not allowed. If it's possible, please tell me how to initialize each dimension?

Upvotes: 1

Views: 133

Answers (3)

Jarod42
Jarod42

Reputation: 217135

Following may help you:

template <typename T, std::size_t N, typename IndexType>
class typed_array
{
public:
    typedef typename std::array<T, N>::const_iterator const_iterator;
    typedef typename std::array<T, N>::iterator iterator;

public:
    const T& operator [] (IndexType index) const { return array[int(index)]; }
    T& operator [] (IndexType index) { return array[int(index)]; }

    // discard other index type
    template <typename U> const T& operator [] (U&&) const = delete;
    template <typename U> T& operator [] (U&&) = delete;

    const_iterator begin() const { return array.begin(); }
    const_iterator end() const { return array.end(); }
    iterator begin() { return array.begin(); }
    iterator end() { return array.end(); }

private:
    std::array<T, N> array;
};

enum class E { A, B, C };

int main(int argc, char *argv[])
{
    typed_array<int, 3, E> a;
    typed_array<typed_array<int, 4, char>, 3, E> b;

    //a[2] = 42; // doesn't compile as expected. `2` is not a `E`
    b[E::A]['\0'] = 42;
    //b[E::A][2] = 42; // doesn't compile as expected. `2` is not a `char`

    return 0;
}

Upvotes: 2

BLUEPIXY
BLUEPIXY

Reputation: 40145

It is impossible as it is because it is array elements of the same type.

struct s_i {
    int i;
    const wchar *wc[7];
};
struct s_e {
    enum Ex e;
    struct s_i i[6];
} ary[3];

Upvotes: 1

Some programmer dude
Some programmer dude

Reputation: 409166

No it's not possible.

What you can to is to make a class that behaves as an enumeration and has a subscript operator which returns another special class (that in general behaves as an int) which has a subscript operator which in turn returns the wchar_t array.

Upvotes: 0

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