From 201352eedfd6e91a4df23aabbb5aded420ada338 Mon Sep 17 00:00:00 2001
From: Alexander McCord <amccord@roblox.com>
Date: Mon, 15 Jul 2024 16:33:53 -0700
Subject: [PATCH] Consistently use `struct`.

---
 EqSat/include/Luau/EGraph.h   | 148 +++++++++++++++++-----------------
 EqSat/include/Luau/Language.h |  15 ++--
 EqSat/include/Luau/Slice.h    |  10 +--
 3 files changed, 87 insertions(+), 86 deletions(-)

diff --git a/EqSat/include/Luau/EGraph.h b/EqSat/include/Luau/EGraph.h
index 3f686895..abccd70c 100644
--- a/EqSat/include/Luau/EGraph.h
+++ b/EqSat/include/Luau/EGraph.h
@@ -15,7 +15,7 @@ namespace Luau::EqSat
 {
 
 template<typename L, typename N>
-class EGraph;
+struct EGraph;
 
 template<typename L, typename N>
 struct Analysis final
@@ -58,8 +58,80 @@ struct EClass final
 
 /// See <https://arxiv.org/pdf/2004.03082>.
 template<typename L, typename N>
-class EGraph final
+struct EGraph final
 {
+    Id find(Id id) const
+    {
+        return unionfind.find(id);
+    }
+
+    std::optional<Id> lookup(const L& enode) const
+    {
+        LUAU_ASSERT(isCanonical(enode));
+
+        if (auto it = hashcons.find(enode); it != hashcons.end())
+            return it->second;
+
+        return std::nullopt;
+    }
+
+    Id add(L enode)
+    {
+        canonicalize(enode);
+
+        if (auto id = lookup(enode))
+            return *id;
+
+        Id id = makeEClass(enode);
+        return id;
+    }
+
+    void merge(Id id1, Id id2)
+    {
+        id1 = find(id1);
+        id2 = find(id2);
+        if (id1 == id2)
+            return;
+
+        unionfind.merge(id1, id2);
+
+        EClass<L, typename N::Data>& eclass1 = get(id1);
+        EClass<L, typename N::Data> eclass2 = std::move(get(id2));
+        classes.erase(id2);
+
+        worklist.reserve(worklist.size() + eclass2.parents.size());
+        for (auto [enode, id] : eclass2.parents)
+            worklist.push_back({std::move(enode), id});
+
+        analysis.join(eclass1.data, eclass2.data);
+    }
+
+    void rebuild()
+    {
+        while (!worklist.empty())
+        {
+            auto [enode, id] = worklist.back();
+            worklist.pop_back();
+            repair(get(find(id)));
+        }
+    }
+
+    size_t size() const
+    {
+        return classes.size();
+    }
+
+    EClass<L, typename N::Data>& operator[](Id id)
+    {
+        return get(find(id));
+    }
+
+    const EClass<L, typename N::Data>& operator[](Id id) const
+    {
+        return const_cast<EGraph*>(this)->get(find(id));
+    }
+
+private:
     Analysis<L, N> analysis;
 
     /// A union-find data structure 𝑈 stores an equivalence relation over e-class ids.
@@ -151,78 +223,6 @@ private:
             eclass.parents.emplace_back(std::move(node.key()), node.mapped());
         }
     }
-
-public:
-    Id find(Id id) const
-    {
-        return unionfind.find(id);
-    }
-
-    std::optional<Id> lookup(const L& enode) const
-    {
-        LUAU_ASSERT(isCanonical(enode));
-
-        if (auto it = hashcons.find(enode); it != hashcons.end())
-            return it->second;
-
-        return std::nullopt;
-    }
-
-    Id add(L enode)
-    {
-        canonicalize(enode);
-
-        if (auto id = lookup(enode))
-            return *id;
-
-        Id id = makeEClass(enode);
-        return id;
-    }
-
-    void merge(Id id1, Id id2)
-    {
-        id1 = find(id1);
-        id2 = find(id2);
-        if (id1 == id2)
-            return;
-
-        unionfind.merge(id1, id2);
-
-        EClass<L, typename N::Data>& eclass1 = get(id1);
-        EClass<L, typename N::Data> eclass2 = std::move(get(id2));
-        classes.erase(id2);
-
-        worklist.reserve(worklist.size() + eclass2.parents.size());
-        for (auto [enode, id] : eclass2.parents)
-            worklist.push_back({std::move(enode), id});
-
-        analysis.join(eclass1.data, eclass2.data);
-    }
-
-    void rebuild()
-    {
-        while (!worklist.empty())
-        {
-            auto [enode, id] = worklist.back();
-            worklist.pop_back();
-            repair(get(find(id)));
-        }
-    }
-
-    size_t size() const
-    {
-        return classes.size();
-    }
-
-    EClass<L, typename N::Data>& operator[](Id id)
-    {
-        return get(find(id));
-    }
-
-    const EClass<L, typename N::Data>& operator[](Id id) const
-    {
-        return const_cast<EGraph*>(this)->get(find(id));
-    }
 };
 
 } // namespace Luau::EqSat
diff --git a/EqSat/include/Luau/Language.h b/EqSat/include/Luau/Language.h
index 2a84a303..c17ac577 100644
--- a/EqSat/include/Luau/Language.h
+++ b/EqSat/include/Luau/Language.h
@@ -158,12 +158,10 @@ struct Field : FieldBase
 };
 
 template<typename Phantom, typename... Fields>
-class NodeFields
+struct NodeFields
 {
     static_assert(std::conjunction<std::is_base_of<FieldBase, Fields>...>::value);
 
-    std::array<Id, sizeof...(Fields)> array;
-
     template<typename T>
     static constexpr int getIndex()
     {
@@ -218,17 +216,17 @@ public:
             return languageHash(value.array);
         }
     };
+
+private:
+    std::array<Id, sizeof...(Fields)> array;
 };
 
 template<typename... Ts>
-class Language final
+struct Language final
 {
-    Variant<Ts...> v;
-
     template<typename T>
     using WithinDomain = std::disjunction<std::is_same<std::decay_t<T>, Ts>...>;
 
-public:
     template<typename T>
     Language(T&& t, std::enable_if_t<WithinDomain<T>::value>* = 0) noexcept
         : v(std::forward<T>(t))
@@ -298,6 +296,9 @@ public:
             return seed;
         }
     };
+
+private:
+    Variant<Ts...> v;
 };
 
 } // namespace Luau::EqSat
diff --git a/EqSat/include/Luau/Slice.h b/EqSat/include/Luau/Slice.h
index 886f0c3e..c1c8f098 100644
--- a/EqSat/include/Luau/Slice.h
+++ b/EqSat/include/Luau/Slice.h
@@ -10,12 +10,8 @@ namespace Luau::EqSat
 {
 
 template<typename T>
-class Slice final
+struct Slice final
 {
-    T* _data;
-    size_t _size;
-
-public:
     Slice()
         : _data(nullptr)
         , _size(0)
@@ -63,6 +59,10 @@ public:
         return _data[i];
     }
 
+public:
+    T* _data;
+    size_t _size;
+
 public:
     T* begin() const
     {