From c5c89a4d5c57fd4691981601ada0d9ffe3cf72d0 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
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 ebd4125e23..b2538f3ea0 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 <typename T>
-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<T>, "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<T>& o) const {
- return std::memcmp(&state, &o.state, sizeof(T)) == 0;
- };
-
- bool operator!=(const HashableStruct<T>& o) const {
- return !(*this == o);
- };
-
- std::size_t Hash() const {
- return Common::ComputeStructHash64(state);
- }
-};
-
struct PairHash {
template <class T1, class T2>
std::size_t operator()(const std::pair<T1, T2>& pair) const noexcept {