Array2D.h

#pragma once
#include <cstdint>
#include <cstring>
#include <memory>
#include <string>
#include <stdexcept>
 
namespace mmind {
 
namespace eye {

template <typename ElementData>
class Array2D
{
public:
    Array2D() : _width(0), _height(0), _pData(nullptr) {}
    ~Array2D() {}

    size_t width() const { return _width; }

    size_t height() const { return _height; }

    bool isEmpty() const { return !_pData; }

    const ElementData* data() const { return _pData.get(); }

    ElementData* data()
    {
        return const_cast<ElementData*>(static_cast<const Array2D<ElementData>&>(*this).data());
    }

    const ElementData& operator[](std::size_t n) const
    {
        if (n >= _height * _width || !_pData)
            throw std::out_of_range("invalid subscript");
        ElementData* data = _pData.get();
        return data[n];
    }

    ElementData& operator[](std::size_t n)
    {
        return const_cast<ElementData&>(static_cast<const Array2D<ElementData>&>(*this)[n]);
    }

    const ElementData& at(uint32_t row, uint32_t col) const
    {
        if (row >= _height || col >= _width || !_pData)
            throw std::out_of_range("invalid subscript");
        ElementData* data = _pData.get();
        return data[row * _width + col];
    }

    ElementData& at(uint32_t row, uint32_t col)
    {
        return const_cast<ElementData&>(
            static_cast<const Array2D<ElementData>&>(*this).at(row, col));
    }

    Array2D<ElementData> clone() const
    {
        Array2D<ElementData> copy;
        copy.resize(_width, _height);
        memcpy(copy.data(), data(), _height * _width * sizeof(ElementData));
        return copy;
    }

    void resize(size_t width, size_t height)
    {
        if (width == 0 || height == 0)
            return release();
 
        if (_width == width && _height == height)
            return;
 
        _width = width;
        _height = height;
        _pData.reset(new ElementData[_width * _height], [](ElementData* p) { delete[] p; });
    }

    void release()
    {
        _pData.reset();
        _width = 0;
        _height = 0;
    }
 
private:
    size_t _width;
    size_t _height;
    std::shared_ptr<ElementData> _pData;
};
 
} // namespace eye
} // namespace mmind