Use plain enum for type

My understanding is that this it's now UB for any value that's not
listed to inhabit Type, so the gcc warning about control reaching the
end of a function with an exhaustive switch where every case returns
should go away now.

ConflictSet.cpp

@@ -174,12 +174,12 @@ int BitSet::firstSetGeq(int i) const {
   return -1;
 }
 
-enum class Type : int8_t {
-  Node0,
-  Node3,
-  Node16,
-  Node48,
-  Node256,
+enum Type {
+  Type_Node0,
+  Type_Node3,
+  Type_Node16,
+  Type_Node48,
+  Type_Node256,
 };
 
 struct Node {
@@ -211,24 +211,25 @@ struct Child {
 };
 
 struct Node0 : Node {
-  Node0() { this->type = Type::Node0; }
+  Node0() { this->type = Type_Node0; }
   uint8_t *partialKey() { return (uint8_t *)(this + 1); }
 };
 
 struct Node3 : Node {
   constexpr static auto kMaxNodes = 3;
+  // Sorted
   uint8_t index[kMaxNodes];
   Child children[kMaxNodes];
-  Node3() { this->type = Type::Node3; }
+  Node3() { this->type = Type_Node3; }
   uint8_t *partialKey() { return (uint8_t *)(this + 1); }
 };
 
 struct Node16 : Node {
-  // Sorted
   constexpr static auto kMaxNodes = 16;
+  // Sorted
   uint8_t index[kMaxNodes];
   Child children[kMaxNodes];
-  Node16() { this->type = Type::Node16; }
+  Node16() { this->type = Type_Node16; }
   uint8_t *partialKey() { return (uint8_t *)(this + 1); }
 };
 
@@ -239,7 +240,7 @@ struct Node48 : Node {
   int8_t index[256];
   Node48() {
     memset(index, -1, 256);
-    this->type = Type::Node48;
+    this->type = Type_Node48;
   }
   uint8_t *partialKey() { return (uint8_t *)(this + 1); }
 };
@@ -248,7 +249,7 @@ struct Node256 : Node {
   BitSet bitSet;
   Child children[256];
   Node256() {
-    this->type = Type::Node256;
+    this->type = Type_Node256;
     for (int i = 0; i < 256; ++i) {
       children[i].child = nullptr;
     }
@@ -365,15 +366,15 @@ private:
 
 uint8_t *Node::partialKey() {
   switch (type) {
-  case Type::Node0:
+  case Type_Node0:
     return ((Node0 *)this)->partialKey();
-  case Type::Node3:
+  case Type_Node3:
     return ((Node3 *)this)->partialKey();
-  case Type::Node16:
+  case Type_Node16:
     return ((Node16 *)this)->partialKey();
-  case Type::Node48:
+  case Type_Node48:
     return ((Node48 *)this)->partialKey();
-  case Type::Node256:
+  case Type_Node256:
     return ((Node256 *)this)->partialKey();
   }
   __builtin_unreachable(); // GCOVR_EXCL_LINE
@@ -451,22 +452,22 @@ template <class NodeT> int getNodeIndex(NodeT *self, uint8_t index) {
 // Precondition - an entry for index must exist in the node
 Node *&getChildExists(Node *self, uint8_t index) {
   switch (self->type) {
-  case Type::Node0:
+  case Type_Node0:
     __builtin_unreachable(); // GCOVR_EXCL_LINE
-  case Type::Node3: {
+  case Type_Node3: {
     auto *self3 = static_cast<Node3 *>(self);
     return self3->children[getNodeIndex(self3, index)].child;
   }
-  case Type::Node16: {
+  case Type_Node16: {
     auto *self16 = static_cast<Node16 *>(self);
     return self16->children[getNodeIndex(self16, index)].child;
   }
-  case Type::Node48: {
+  case Type_Node48: {
     auto *self48 = static_cast<Node48 *>(self);
     assert(self48->bitSet.test(index));
     return self48->children[self48->index[index]].child;
   }
-  case Type::Node256: {
+  case Type_Node256: {
     auto *self256 = static_cast<Node256 *>(self);
     assert(self256->bitSet.test(index));
     return self256->children[index].child;
@@ -481,24 +482,24 @@ Node *&getInTree(Node *n, ConflictSet::Impl *);
 
 Node *getChild(Node *self, uint8_t index) {
   switch (self->type) {
-  case Type::Node0:
+  case Type_Node0:
     return nullptr;
-  case Type::Node3: {
+  case Type_Node3: {
     auto *self3 = static_cast<Node3 *>(self);
     int i = getNodeIndex(self3, index);
     return i < 0 ? nullptr : self3->children[i].child;
   }
-  case Type::Node16: {
+  case Type_Node16: {
     auto *self16 = static_cast<Node16 *>(self);
     int i = getNodeIndex(self16, index);
     return i < 0 ? nullptr : self16->children[i].child;
   }
-  case Type::Node48: {
+  case Type_Node48: {
     auto *self48 = static_cast<Node48 *>(self);
     int i = self48->index[index];
     return i < 0 ? nullptr : self48->children[i].child;
   }
-  case Type::Node256: {
+  case Type_Node256: {
     auto *self256 = static_cast<Node256 *>(self);
     return self256->children[index].child;
   }
@@ -568,15 +569,15 @@ int getChildGeq(Node *self, int child) {
     return -1;
   }
   switch (self->type) {
-  case Type::Node0:
+  case Type_Node0:
     return -1;
-  case Type::Node3:
+  case Type_Node3:
     return getChildGeqSimd(static_cast<Node3 *>(self), child);
-  case Type::Node16:
+  case Type_Node16:
     return getChildGeqSimd(static_cast<Node16 *>(self), child);
-  case Type::Node48:
+  case Type_Node48:
     [[fallthrough]];
-  case Type::Node256: {
+  case Type_Node256: {
     static_assert(offsetof(Node48, bitSet) == offsetof(Node256, bitSet));
     auto *self48 = static_cast<Node48 *>(self);
     return self48->bitSet.firstSetGeq(child);
@@ -613,30 +614,30 @@ Node *&getOrCreateChild(Node *&self, uint8_t index,
 
   // Fast path for if it exists already
   switch (self->type) {
-  case Type::Node0:
+  case Type_Node0:
     break;
-  case Type::Node3: {
+  case Type_Node3: {
     auto *self3 = static_cast<Node3 *>(self);
     int i = getNodeIndex(self3, index);
     if (i >= 0) {
       return self3->children[i].child;
     }
   } break;
-  case Type::Node16: {
+  case Type_Node16: {
     auto *self16 = static_cast<Node16 *>(self);
     int i = getNodeIndex(self16, index);
     if (i >= 0) {
       return self16->children[i].child;
     }
   } break;
-  case Type::Node48: {
+  case Type_Node48: {
     auto *self48 = static_cast<Node48 *>(self);
     int secondIndex = self48->index[index];
     if (secondIndex >= 0) {
       return self48->children[secondIndex].child;
     }
   } break;
-  case Type::Node256: {
+  case Type_Node256: {
     auto *self256 = static_cast<Node256 *>(self);
     if (auto &result = self256->children[index].child; result != nullptr) {
       return result;
@@ -645,7 +646,7 @@ Node *&getOrCreateChild(Node *&self, uint8_t index,
   }
 
   switch (self->type) {
-  case Type::Node0: {
+  case Type_Node0: {
     auto *self0 = static_cast<Node0 *>(self);
 
     auto *newSelf = allocators->node3.allocate(self->partialKeyLen);
@@ -657,7 +658,7 @@ Node *&getOrCreateChild(Node *&self, uint8_t index,
 
     goto insert3;
   }
-  case Type::Node3: {
+  case Type_Node3: {
     if (self->numChildren == Node3::kMaxNodes) {
       auto *self3 = static_cast<Node3 *>(self);
       auto *newSelf = allocators->node16.allocate(self->partialKeyLen);
@@ -693,7 +694,7 @@ Node *&getOrCreateChild(Node *&self, uint8_t index,
     result = nullptr;
     return result;
   }
-  case Type::Node16: {
+  case Type_Node16: {
     if (self->numChildren == Node16::kMaxNodes) {
       auto *self16 = static_cast<Node16 *>(self);
       auto *newSelf = allocators->node48.allocate(self->partialKeyLen);
@@ -717,7 +718,7 @@ Node *&getOrCreateChild(Node *&self, uint8_t index,
 
   insert16:
     auto *self16 = static_cast<Node16 *>(self);
-    assert(self->type == Type::Node16);
+    assert(self->type == Type_Node16);
 
     ++self->numChildren;
     int i = 0;
@@ -735,7 +736,7 @@ Node *&getOrCreateChild(Node *&self, uint8_t index,
     result = nullptr;
     return result;
   }
-  case Type::Node48: {
+  case Type_Node48: {
 
     if (self->numChildren == 48) {
       auto *self48 = static_cast<Node48 *>(self);
@@ -766,7 +767,7 @@ Node *&getOrCreateChild(Node *&self, uint8_t index,
     result = nullptr;
     return result;
   }
-  case Type::Node256: {
+  case Type_Node256: {
   insert256:
     auto *self256 = static_cast<Node256 *>(self);
     ++self->numChildren;
@@ -804,7 +805,7 @@ template <bool kUseFreeList>
 void makeCapacityAtLeast(Node *&self, int capacity, NodeAllocators *allocators,
                          ConflictSet::Impl *impl) {
   switch (self->type) {
-  case Type::Node0: {
+  case Type_Node0: {
     auto *self0 = (Node0 *)self;
     auto *newSelf = allocators->node0.allocate(capacity);
     memcpy((char *)newSelf + kNodeCopyBegin, (char *)self + kNodeCopyBegin,
@@ -818,7 +819,7 @@ void makeCapacityAtLeast(Node *&self, int capacity, NodeAllocators *allocators,
     }
     self = newSelf;
   } break;
-  case Type::Node3: {
+  case Type_Node3: {
     auto *self3 = (Node3 *)self;
     auto *newSelf = allocators->node3.allocate(capacity);
     memcpy((char *)newSelf + kNodeCopyBegin, (char *)self + kNodeCopyBegin,
@@ -838,7 +839,7 @@ void makeCapacityAtLeast(Node *&self, int capacity, NodeAllocators *allocators,
     }
     self = newSelf;
   } break;
-  case Type::Node16: {
+  case Type_Node16: {
     auto *self16 = (Node16 *)self;
     auto *newSelf = allocators->node16.allocate(capacity);
     memcpy((char *)newSelf + kNodeCopyBegin, (char *)self + kNodeCopyBegin,
@@ -858,7 +859,7 @@ void makeCapacityAtLeast(Node *&self, int capacity, NodeAllocators *allocators,
     }
     self = newSelf;
   } break;
-  case Type::Node48: {
+  case Type_Node48: {
     auto *self48 = (Node48 *)self;
     auto *newSelf = allocators->node48.allocate(capacity);
     memcpy((char *)newSelf + kNodeCopyBegin, (char *)self + kNodeCopyBegin,
@@ -882,7 +883,7 @@ void makeCapacityAtLeast(Node *&self, int capacity, NodeAllocators *allocators,
     }
     self = newSelf;
   } break;
-  case Type::Node256: {
+  case Type_Node256: {
     auto *self256 = (Node256 *)self;
     auto *newSelf = allocators->node256.allocate(capacity);
     memcpy((char *)newSelf + kNodeCopyBegin, (char *)self + kNodeCopyBegin,
@@ -926,9 +927,9 @@ void maybeDownsize(Node *self, NodeAllocators *allocators,
 #endif
 
   switch (self->type) {
-  case Type::Node0:
+  case Type_Node0:
     __builtin_unreachable(); // GCOVR_EXCL_LINE
-  case Type::Node3: {
+  case Type_Node3: {
     auto *self3 = (Node3 *)self;
     if (self->numChildren == 0) {
       auto *newSelf = allocators->node0.allocate(self->partialKeyLen);
@@ -980,7 +981,7 @@ void maybeDownsize(Node *self, NodeAllocators *allocators,
       }
     }
   } break;
-  case Type::Node16:
+  case Type_Node16:
     if (self->numChildren + int(self->entryPresent) < kMinChildrenNode16) {
       auto *self16 = (Node16 *)self;
       auto *newSelf = allocators->node3.allocate(self->partialKeyLen);
@@ -997,7 +998,7 @@ void maybeDownsize(Node *self, NodeAllocators *allocators,
       allocators->node16.release(self16);
     }
     break;
-  case Type::Node48:
+  case Type_Node48:
     if (self->numChildren + int(self->entryPresent) < kMinChildrenNode48) {
       auto *self48 = (Node48 *)self;
       auto *newSelf = allocators->node16.allocate(self->partialKeyLen);
@@ -1024,7 +1025,7 @@ void maybeDownsize(Node *self, NodeAllocators *allocators,
       allocators->node48.release(self48);
     }
     break;
-  case Type::Node256:
+  case Type_Node256:
     if (self->numChildren + int(self->entryPresent) < kMinChildrenNode256) {
       auto *self256 = (Node256 *)self;
       auto *newSelf = allocators->node48.allocate(self->partialKeyLen);
@@ -1076,27 +1077,27 @@ Node *erase(Node *self, NodeAllocators *allocators, ConflictSet::Impl *impl,
   }
 
   switch (self->type) {
-  case Type::Node0:
+  case Type_Node0:
     allocators->node0.release((Node0 *)self);
     break;
-  case Type::Node3:
+  case Type_Node3:
     allocators->node3.release((Node3 *)self);
     break;
-  case Type::Node16:
+  case Type_Node16:
     allocators->node16.release((Node16 *)self);
     break;
-  case Type::Node48:
+  case Type_Node48:
     allocators->node48.release((Node48 *)self);
     break;
-  case Type::Node256:
+  case Type_Node256:
     allocators->node256.release((Node256 *)self);
     break;
   }
 
   switch (parent->type) {
-  case Type::Node0:
+  case Type_Node0:
     __builtin_unreachable(); // GCOVR_EXCL_LINE
-  case Type::Node3: {
+  case Type_Node3: {
     auto *parent3 = static_cast<Node3 *>(parent);
     int nodeIndex = getNodeIndex(parent3, parentsIndex);
     assert(nodeIndex >= 0);
@@ -1107,7 +1108,7 @@ Node *erase(Node *self, NodeAllocators *allocators, ConflictSet::Impl *impl,
             sizeof(parent3->children[0]) *
                 (parent->numChildren - (nodeIndex + 1)));
   } break;
-  case Type::Node16: {
+  case Type_Node16: {
     auto *parent16 = static_cast<Node16 *>(parent);
     int nodeIndex = getNodeIndex(parent16, parentsIndex);
     assert(nodeIndex >= 0);
@@ -1118,7 +1119,7 @@ Node *erase(Node *self, NodeAllocators *allocators, ConflictSet::Impl *impl,
             sizeof(parent16->children[0]) *
                 (parent->numChildren - (nodeIndex + 1)));
   } break;
-  case Type::Node48: {
+  case Type_Node48: {
     auto *parent48 = static_cast<Node48 *>(parent);
     parent48->bitSet.reset(parentsIndex);
     int8_t toRemoveChildrenIndex =
@@ -1133,7 +1134,7 @@ Node *erase(Node *self, NodeAllocators *allocators, ConflictSet::Impl *impl,
                           .child->parentsIndex] = toRemoveChildrenIndex;
     }
   } break;
-  case Type::Node256: {
+  case Type_Node256: {
     auto *parent256 = static_cast<Node256 *>(parent);
     parent256->bitSet.reset(parentsIndex);
     parent256->children[parentsIndex].child = nullptr;
@@ -1450,10 +1451,10 @@ int64_t maxBetweenExclusive(Node *n, int begin, int end) {
     }
   }
   switch (n->type) {
-  case Type::Node0:
+  case Type_Node0:
     // We would have returned above, after not finding a child
     __builtin_unreachable(); // GCOVR_EXCL_LINE
-  case Type::Node3: {
+  case Type_Node3: {
     auto *self = static_cast<Node3 *>(n);
     for (int i = 0; i < self->numChildren && self->index[i] < end; ++i) {
       if (begin <= self->index[i]) {
@@ -1461,7 +1462,7 @@ int64_t maxBetweenExclusive(Node *n, int begin, int end) {
       }
     }
   } break;
-  case Type::Node16: {
+  case Type_Node16: {
     auto *self = static_cast<Node16 *>(n);
     for (int i = 0; i < self->numChildren && self->index[i] < end; ++i) {
       if (begin <= self->index[i]) {
@@ -1469,7 +1470,7 @@ int64_t maxBetweenExclusive(Node *n, int begin, int end) {
       }
     }
   } break;
-  case Type::Node48: {
+  case Type_Node48: {
     auto *self = static_cast<Node48 *>(n);
     self->bitSet.forEachInRange(
         [&](int i) {
@@ -1479,7 +1480,7 @@ int64_t maxBetweenExclusive(Node *n, int begin, int end) {
         begin, end);
     break;
   }
-  case Type::Node256: {
+  case Type_Node256: {
     auto *self = static_cast<Node256 *>(n);
     self->bitSet.forEachInRange(
         [&](int i) {
@@ -2318,24 +2319,24 @@ int64_t &maxVersion(Node *n, ConflictSet::Impl *impl) {
     return impl->rootMaxVersion;
   }
   switch (n->type) {
-  case Type::Node0:
+  case Type_Node0:
     __builtin_unreachable(); // GCOVR_EXCL_LINE
-  case Type::Node3: {
+  case Type_Node3: {
     auto *n3 = static_cast<Node3 *>(n);
     int i = getNodeIndex(n3, index);
     return n3->children[i].childMaxVersion;
   }
-  case Type::Node16: {
+  case Type_Node16: {
     auto *n16 = static_cast<Node16 *>(n);
     int i = getNodeIndex(n16, index);
     return n16->children[i].childMaxVersion;
   }
-  case Type::Node48: {
+  case Type_Node48: {
     auto *n48 = static_cast<Node48 *>(n);
     assert(n48->bitSet.test(index));
     return n48->children[n48->index[index]].childMaxVersion;
   }
-  case Type::Node256: {
+  case Type_Node256: {
     auto *n256 = static_cast<Node256 *>(n);
     assert(n256->bitSet.test(index));
     return n256->children[index].childMaxVersion;
@@ -2595,19 +2596,19 @@ Iterator firstGeq(Node *n, std::string_view key) {
 [[maybe_unused]] void checkMemoryBoundInvariants(Node *node, bool &success) {
   int minNumChildren;
   switch (node->type) {
-  case Type::Node0:
+  case Type_Node0:
     minNumChildren = 0;
     break;
-  case Type::Node3:
+  case Type_Node3:
     minNumChildren = kMinChildrenNode3;
     break;
-  case Type::Node16:
+  case Type_Node16:
     minNumChildren = kMinChildrenNode16;
     break;
-  case Type::Node48:
+  case Type_Node48:
     minNumChildren = kMinChildrenNode48;
     break;
-  case Type::Node256:
+  case Type_Node256:
     minNumChildren = kMinChildrenNode256;
     break;
   }