569802e00f
This ensures that an array is indexed by the appropriate type. Indexing a mouse array with a joystick index is undefined behavior, and with this change, such undefined behavior is now a compilation error.
50 lines
1.6 KiB
C++
50 lines
1.6 KiB
C++
/*
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* This file is part of the DXX-Rebirth project <https://www.dxx-rebirth.com/>.
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* It is copyright by its individual contributors, as recorded in the
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* project's Git history. See COPYING.txt at the top level for license
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* terms and a link to the Git history.
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*/
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#pragma once
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#include <array>
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#include <cstddef>
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namespace dcx {
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/* Wrap a std::array and override the normal indexing operations to take
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* an instance of type `E`. This is intended for use where `E` is an
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* instance of `enum class`. When `E` is an `enum class`, instances of
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* `E` cannot implicitly convert to `std::array::size_type`, and so
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* would require a cast in the caller if this wrapper were not used.
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* Using this wrapper moves the casts into the wrapper, after the
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* compiler has checked that the argument is the right type of `enum
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* class`. This prevents accidentally using an incorrect `enum class`.
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*
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* Other types for E are not likely to be useful, but are not blocked.
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*/
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template <typename T, std::size_t N, typename E>
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struct enumerated_array : std::array<T, N>
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{
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using base_type = std::array<T, N>;
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using typename base_type::reference;
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using typename base_type::const_reference;
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constexpr reference at(E position)
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{
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return this->base_type::at(static_cast<std::size_t>(position));
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}
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constexpr const_reference at(E position) const
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{
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return this->base_type::at(static_cast<std::size_t>(position));
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}
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constexpr reference operator[](E position)
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{
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return this->base_type::operator[](static_cast<std::size_t>(position));
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}
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constexpr const_reference operator[](E position) const
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{
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return this->base_type::operator[](static_cast<std::size_t>(position));
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}
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};
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}
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