/*
* This file is part of the DXX-Rebirth project <https://www.dxx-rebirth.com/>.
* It is copyright by its individual contributors, as recorded in the
* project's Git history. See COPYING.txt at the top level for license
* terms and a link to the Git history.
*/
#pragma once
#include "dxxsconf.h"
#include <array>
#include <cstddef>
namespace dcx {
/* Wrap a std::array and override the normal indexing operations to take
* an instance of type `E`. This is intended for use where `E` is an
* instance of `enum class`. When `E` is an `enum class`, instances of
* `E` cannot implicitly convert to `std::array::size_type`, and so
* would require a cast in the caller if this wrapper were not used.
* Using this wrapper moves the casts into the wrapper, after the
* compiler has checked that the argument is the right type of `enum
* class`. This prevents accidentally using an incorrect `enum class`.
*
* Other types for E are not likely to be useful, but are not blocked.
*/
template <typename T, std::size_t N, typename E>
struct enumerated_array : std::array<T, N>
{
using base_type = std::array<T, N>;
using typename base_type::reference;
using typename base_type::const_reference;
constexpr reference at(E position)
{
return this->base_type::at(static_cast<std::size_t>(position));
}
constexpr const_reference at(E position) const
{
return this->base_type::at(static_cast<std::size_t>(position));
}
constexpr reference operator[](E position)
{
return this->base_type::operator[](static_cast<std::size_t>(position));
}
constexpr const_reference operator[](E position) const
{
return this->base_type::operator[](static_cast<std::size_t>(position));
}
__attribute_warn_unused_result
static constexpr bool valid_index(std::size_t s)
{
return s < N;
}
__attribute_warn_unused_result
static constexpr bool valid_index(E e)
{
return valid_index(static_cast<std::size_t>(e));
}
};
}