From c5c89a4d5c57fd4691981601ada0d9ffe3cf72d0 Mon Sep 17 00:00:00 2001 From: Lioncash Date: Wed, 13 Nov 2019 14:58:40 -0500 Subject: [PATCH] common/hash: Remove unused HashableStruct This is unused, so it can be removed. There's better ways of ensuring zeroed out padding bits, like using zero-initialization, anyhow. --- src/common/hash.h | 35 ----------------------------------- 1 file changed, 35 deletions(-) diff --git a/src/common/hash.h b/src/common/hash.h index ebd4125e2..b2538f3ea 100644 --- a/src/common/hash.h +++ b/src/common/hash.h @@ -35,41 +35,6 @@ static inline u64 ComputeStructHash64(const T& data) { return ComputeHash64(&data, sizeof(data)); } -/// A helper template that ensures the padding in a struct is initialized by memsetting to 0. -template -struct HashableStruct { - // In addition to being trivially copyable, T must also have a trivial default constructor, - // because any member initialization would be overridden by memset - static_assert(std::is_trivial_v, "Type passed to HashableStruct must be trivial"); - /* - * We use a union because "implicitly-defined copy/move constructor for a union X copies the - * object representation of X." and "implicitly-defined copy assignment operator for a union X - * copies the object representation (3.9) of X." = Bytewise copy instead of memberwise copy. - * This is important because the padding bytes are included in the hash and comparison between - * objects. - */ - union { - T state; - }; - - HashableStruct() { - // Memset structure to zero padding bits, so that they will be deterministic when hashing - std::memset(&state, 0, sizeof(T)); - } - - bool operator==(const HashableStruct& o) const { - return std::memcmp(&state, &o.state, sizeof(T)) == 0; - }; - - bool operator!=(const HashableStruct& o) const { - return !(*this == o); - }; - - std::size_t Hash() const { - return Common::ComputeStructHash64(state); - } -}; - struct PairHash { template std::size_t operator()(const std::pair& pair) const noexcept {