diff --git a/yoga/Bitfield.h b/yoga/Bitfield.h deleted file mode 100644 index 02645961..00000000 --- a/yoga/Bitfield.h +++ /dev/null @@ -1,145 +0,0 @@ -/* - * Copyright (c) Facebook, Inc. and its affiliates. - * - * This source code is licensed under the MIT license found in the - * LICENSE file in the root directory of this source tree. - */ - -#pragma once - -#include -#include -#include -#include - -namespace facebook { -namespace yoga { - -namespace detail { - -constexpr size_t log2ceil(size_t n) { - return n < 1 ? 0 : (1 + log2ceil(n / 2)); -} - -// The number of bits necessary to represent enums defined with YG_ENUM_SEQ_DECL -template -constexpr size_t bitWidth() { - static_assert( - enums::count() > 0, "Enums must have at least one entries"); - return log2ceil(enums::count() - 1); -} - -// Number of bits needed for a boolean -template <> -constexpr size_t bitWidth() { - return 1; -} - -template -struct BitTraits {}; - -template -struct BitTraits { - // Base cases - static constexpr size_t width(size_t) { return 0; } - static constexpr size_t shift(size_t) { return 0; } -}; - -template -struct BitTraits { - using Rest = BitTraits; - - static constexpr size_t width(size_t idx) { - return idx == 0 ? bitWidth() : Rest::width(idx - 1); - } - - static constexpr size_t shift(size_t idx) { - return idx == 0 ? Rest::width(0) + Rest::shift(0) : Rest::shift(idx - 1); - } - - static constexpr U mask(size_t idx) { - return ((U{1} << width(idx)) - 1) << shift(idx); - } -}; - -template -struct IndexedType { - using Type = typename IndexedType::Type; -}; - -template -struct IndexedType<0, T, Ts...> { - using Type = T; -}; - -} // namespace detail - -template -class Bitfield { - static_assert( - std::is_integral::value, - "Bitfield needs an integral storage type"); - static_assert( - std::is_unsigned::value, - "Bitfield needs an unsigned storage type"); - static_assert(sizeof...(Fields) > 0, "Bitfield needs at least one member"); - - using BitTraits = detail::BitTraits; - -#if !defined(_MSC_VER) || _MSC_VER > 1914 - static_assert( - BitTraits::shift(0) + BitTraits::width(0) <= - std::numeric_limits::digits, - "Specified storage type is too narrow to hold all types"); -#endif - - template - using TypeAt = typename detail::IndexedType::Type; - - template - static constexpr Storage initStorage(Value value, Values... values) { - return ((value << BitTraits::shift(Idx)) & BitTraits::mask(Idx)) | - initStorage(values...); - } - - template - static constexpr Storage initStorage() { - return Storage{0}; - } - - Storage storage_ = 0; - -public: - template - class Ref { - Bitfield& bitfield_; - - public: - Ref(Bitfield& bitfield) : bitfield_(bitfield) {} - Ref& operator=(TypeAt value) { - bitfield_.storage_ = (bitfield_.storage_ & ~BitTraits::mask(Idx)) | - ((value << BitTraits::shift(Idx)) & BitTraits::mask(Idx)); - return *this; - } - operator TypeAt() const { - return const_cast(bitfield_).at(); - } - }; - - constexpr Bitfield() = default; - constexpr Bitfield(Fields... values) : storage_{initStorage<0>(values...)} {} - - template - constexpr TypeAt at() const { - return static_cast>( - (storage_ & BitTraits::mask(Idx)) >> BitTraits::shift(Idx)); - } - - template - Ref at() { - return {*this}; - } -}; - -} // namespace yoga -} // namespace facebook