diff options
| -rw-r--r-- | src/common/bit_field.h | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/src/common/bit_field.h b/src/common/bit_field.h index bf803da8d..21e07925d 100644 --- a/src/common/bit_field.h +++ b/src/common/bit_field.h @@ -117,21 +117,21 @@ private: // We don't delete it because we want BitField to be trivially copyable. constexpr BitField& operator=(const BitField&) = default; - // StorageType is T for non-enum types and the underlying type of T if + // UnderlyingType is T for non-enum types and the underlying type of T if // T is an enumeration. Note that T is wrapped within an enable_if in the // former case to workaround compile errors which arise when using // std::underlying_type<T>::type directly. - using StorageType = typename std::conditional_t<std::is_enum<T>::value, std::underlying_type<T>, - std::enable_if<true, T>>::type; + using UnderlyingType = typename std::conditional_t<std::is_enum_v<T>, std::underlying_type<T>, + std::enable_if<true, T>>::type; - // Unsigned version of StorageType - using StorageTypeU = std::make_unsigned_t<StorageType>; + // We store the value as the unsigned type to avoid undefined behaviour on value shifting + using StorageType = std::make_unsigned_t<UnderlyingType>; public: /// Constants to allow limited introspection of fields if needed static constexpr std::size_t position = Position; static constexpr std::size_t bits = Bits; - static constexpr StorageType mask = (((StorageTypeU)~0) >> (8 * sizeof(T) - bits)) << position; + static constexpr StorageType mask = (((StorageType)~0) >> (8 * sizeof(T) - bits)) << position; /** * Formats a value by masking and shifting it according to the field parameters. A value @@ -148,11 +148,12 @@ public: * union in a constexpr context. */ static constexpr FORCE_INLINE T ExtractValue(const StorageType& storage) { - if (std::numeric_limits<T>::is_signed) { + if constexpr (std::numeric_limits<UnderlyingType>::is_signed) { std::size_t shift = 8 * sizeof(T) - bits; - return (T)((storage << (shift - position)) >> shift); + return static_cast<T>(static_cast<UnderlyingType>(storage << (shift - position)) >> + shift); } else { - return (T)((storage & mask) >> position); + return static_cast<T>((storage & mask) >> position); } } |