cpp-mathmatic-matrix/include/math/matrix/row_reference.hpp

#pragma once

#include <cstdlib>
#include <stdexcept>

#include "expect/expect.hpp"
#include "math/vector/vector.hpp"

namespace math { namespace matrix {
  template <typename T, size_t C> class row_reference {
  private:
    row_reference(T (&h)[C]) : _handle(h) {}

  public:
    row_reference(row_reference const &) = delete;
    row_reference(row_reference &&) = default;

    template <typename S>
    row_reference & operator=(row_reference<S, C> const & other) {
      VECTOR_FOR_EACH_RANGE(i, C) { _handle[i] = other[i]; }
      return *this;
    }

    T const & operator[](size_t col) const { return _handle[col]; }
    T & operator[](size_t col) { return _handle[col]; }
    T const & at(size_t col) const {
      expects(col < C, std::out_of_range, "column index out of range");
      return operator[](col);
    }
    T & at(size_t col) {
      expects(col < C, std::out_of_range, "column index out of range");
      return operator[](col);
    }

  private:
    template <typename _T, size_t R, size_t _C> friend class matrix;
    T (&_handle)[C];
  };
}}