diff --git a/meson.build b/meson.build
index 3d17d663b..46945ee0b 100644
--- a/meson.build
+++ b/meson.build
@@ -40,7 +40,6 @@ endif
 add_project_arguments(global_cpp_defs, language: ['cpp', 'c'])
 
 global_cpp_args = [
-  '-fpermissive',
   '-Wshift-count-overflow',
   '-pipe',
 ]
diff --git a/minecraft/Minecraft.World/net/minecraft/world/entity/item/FallingTile.cpp b/minecraft/Minecraft.World/net/minecraft/world/entity/item/FallingTile.cpp
index aa088e0e8..12414a0b6 100644
--- a/minecraft/Minecraft.World/net/minecraft/world/entity/item/FallingTile.cpp
+++ b/minecraft/Minecraft.World/net/minecraft/world/entity/item/FallingTile.cpp
@@ -122,9 +122,9 @@ void FallingTile::tick() {
                         if (tileEntity != nullptr) {
                             CompoundTag* swap = new CompoundTag();
                             tileEntity->save(swap);
-                            std::vector<Tag*>* allTags = tileData->getAllTags();
-                            for (auto it = allTags->begin();
-                                 it != allTags->end(); ++it) {
+                            std::vector<Tag*> allTags = tileData->getAllTags();
+                            for (auto it = allTags.begin();
+                                 it != allTags.end(); ++it) {
                                 Tag* tag = *it;
                                 if (tag->getName().compare(L"x") == 0 ||
                                     tag->getName().compare(L"y") == 0 ||
@@ -132,7 +132,6 @@ void FallingTile::tick() {
                                     continue;
                                 swap->put(tag->getName(), tag->copy());
                             }
-                            delete allTags;
                             tileEntity->load(swap);
                             tileEntity->setChanged();
                         }
diff --git a/minecraft/Minecraft.World/net/minecraft/world/level/BaseMobSpawner.cpp b/minecraft/Minecraft.World/net/minecraft/world/level/BaseMobSpawner.cpp
index 1ebdb0348..8f7656571 100644
--- a/minecraft/Minecraft.World/net/minecraft/world/level/BaseMobSpawner.cpp
+++ b/minecraft/Minecraft.World/net/minecraft/world/level/BaseMobSpawner.cpp
@@ -133,12 +133,11 @@ std::shared_ptr<Entity> BaseMobSpawner::loadDataAndAddEntity(
         CompoundTag* data = new CompoundTag();
         entity->save(data);
 
-        std::vector<Tag*>* tags = getNextSpawnData()->tag->getAllTags();
-        for (auto it = tags->begin(); it != tags->end(); ++it) {
+        std::vector<Tag*> tags = getNextSpawnData()->tag->getAllTags();
+        for (auto it = tags.begin(); it != tags.end(); ++it) {
             Tag* tag = *it;
             data->put(tag->getName(), tag->copy());
         }
-        delete tags;
 
         entity->load(data);
         if (entity->level != nullptr) entity->level->addEntity(entity);
@@ -153,13 +152,12 @@ std::shared_ptr<Entity> BaseMobSpawner::loadDataAndAddEntity(
                 CompoundTag* mountData = new CompoundTag();
                 mount->save(mountData);
 
-                std::vector<Tag*>* ridingTags = ridingTag->getAllTags();
-                for (auto it = ridingTags->begin(); it != ridingTags->end();
+                std::vector<Tag*> ridingTags = ridingTag->getAllTags();
+                for (auto it = ridingTags.begin(); it != ridingTags.end();
                      ++it) {
                     Tag* tag = *it;
                     mountData->put(tag->getName(), tag->copy());
                 }
-                delete ridingTags;
                 mount->load(mountData);
                 mount->moveTo(rider->x, rider->y, rider->z, rider->yRot,
                               rider->xRot);
diff --git a/minecraft/Minecraft.World/net/minecraft/world/level/GameRules.cpp b/minecraft/Minecraft.World/net/minecraft/world/level/GameRules.cpp
index 7c40547a2..381af0602 100644
--- a/minecraft/Minecraft.World/net/minecraft/world/level/GameRules.cpp
+++ b/minecraft/Minecraft.World/net/minecraft/world/level/GameRules.cpp
@@ -127,8 +127,8 @@ CompoundTag *GameRules::createTag()
 
 void GameRules::loadFromTag(CompoundTag *tag)
 {
-        vector<Tag *> *allTags = tag->getAllTags();
-        for (auto it = allTags->begin(); it != allTags->end(); ++it)
+        vector<Tag *> allTags = tag->getAllTags();
+        for (auto it = allTags.begin(); it != allTags.end(); ++it)
         {
                 Tag *ruleTag = *it;
                 std::wstring ruleName = ruleTag->getName();
@@ -136,7 +136,6 @@ void GameRules::loadFromTag(CompoundTag *tag)
 
                 set(ruleName, value);
         }
-        delete allTags;
 }
 
 // Need to delete returned vector.
diff --git a/minecraft/Minecraft.World/net/minecraft/world/level/levelgen/structure/StructureFeature.cpp b/minecraft/Minecraft.World/net/minecraft/world/level/levelgen/structure/StructureFeature.cpp
index db724ddea..d68807c07 100644
--- a/minecraft/Minecraft.World/net/minecraft/world/level/levelgen/structure/StructureFeature.cpp
+++ b/minecraft/Minecraft.World/net/minecraft/world/level/levelgen/structure/StructureFeature.cpp
@@ -252,8 +252,8 @@ void StructureFeature::restoreSavedData(Level* level) {
         } else {
             CompoundTag* fullTag = savedData->getFullTag();
 
-            std::vector<Tag*>* allTags = fullTag->getAllTags();
-            for (auto it = allTags->begin(); it != allTags->end(); ++it) {
+            std::vector<Tag*> allTags = fullTag->getAllTags();
+            for (auto it = allTags.begin(); it != allTags.end(); ++it) {
                 Tag* featureTag = *it;
                 if (featureTag->getId() == Tag::TAG_Compound) {
                     CompoundTag* ct = (CompoundTag*)featureTag;
diff --git a/minecraft/Minecraft.World/net/minecraft/world/level/storage/SavedDataStorage.cpp b/minecraft/Minecraft.World/net/minecraft/world/level/storage/SavedDataStorage.cpp
index 58ddfc21f..395906dd4 100644
--- a/minecraft/Minecraft.World/net/minecraft/world/level/storage/SavedDataStorage.cpp
+++ b/minecraft/Minecraft.World/net/minecraft/world/level/storage/SavedDataStorage.cpp
@@ -134,10 +134,10 @@ void SavedDataStorage::loadAuxValues() {
         dis.close();
 
         Tag* tag;
-        std::vector<Tag*>* allTags = tags->getAllTags();
-        auto itEnd = allTags->end();
-        for (auto it = allTags->begin(); it != itEnd; it++) {
-            tag = *it;  // tags->getAllTags()->at(i);
+        std::vector<Tag*> allTags = tags->getAllTags();
+        auto itEnd = allTags.end();
+        for (auto it = allTags.begin(); it != itEnd; it++) {
+            tag = *it;
 
             if (dynamic_cast<ShortTag*>(tag) != nullptr) {
                 ShortTag* sTag = (ShortTag*)tag;
@@ -146,7 +146,6 @@ void SavedDataStorage::loadAuxValues() {
                 usedAuxIds.insert(uaiMapType::value_type(id, val));
             }
         }
-        delete allTags;
     }
 }
 
diff --git a/minecraft/nbt/include/nbt/CompoundTag.h b/minecraft/nbt/include/nbt/CompoundTag.h
index 919e4c7a6..e9df4f61a 100644
--- a/minecraft/nbt/include/nbt/CompoundTag.h
+++ b/minecraft/nbt/include/nbt/CompoundTag.h
@@ -11,21 +11,20 @@
 #include "ByteArrayTag.h"
 #include "IntArrayTag.h"
 
+#include <memory>
 #include <unordered_map>
 
 class CompoundTag : public Tag {
 private:
-    std::unordered_map<std::wstring, Tag*> tags;
+    std::unordered_map<std::wstring, std::unique_ptr<Tag>> tags;
 
 public:
     CompoundTag() : Tag(L"") {}
     CompoundTag(const std::wstring& name) : Tag(name) {}
 
     void write(DataOutput* dos) {
-        auto itEnd = tags.end();
-        for (std::unordered_map<std::wstring, Tag*>::iterator it = tags.begin();
-             it != itEnd; it++) {
-            Tag::writeNamedTag(it->second, dos);
+        for (auto& [key, value] : tags) {
+            Tag::writeNamedTag(value.get(), dos);
         }
         dos->writeByte(Tag::TAG_End);
     }
@@ -39,22 +38,19 @@ public:
             return;
         }
         tags.clear();
-        Tag* tag;
-        while ((tag = Tag::readNamedTag(dis))->getId() != Tag::TAG_End) {
-            tags[tag->getName()] = tag;
+        for (;;) {
+            std::unique_ptr<Tag> tag(Tag::readNamedTag(dis));
+            if (tag->getId() == Tag::TAG_End) break;
+            auto name = tag->getName();
+            tags[name] = std::move(tag);
         }
-        delete tag;
     }
 
-    std::vector<Tag*>* getAllTags()  // 4J - was collection
-    {
-        // 4J - was return tags.values();
-        std::vector<Tag*>* ret = new std::vector<Tag*>;
-
-        auto itEnd = tags.end();
-        for (std::unordered_map<std::wstring, Tag*>::iterator it = tags.begin();
-             it != itEnd; it++) {
-            ret->push_back(it->second);
+    std::vector<Tag*> getAllTags() {
+        std::vector<Tag*> ret;
+        ret.reserve(tags.size());
+        for (auto& [key, value] : tags) {
+            ret.push_back(value.get());
         }
         return ret;
     }
@@ -62,47 +58,49 @@ public:
     uint8_t getId() { return TAG_Compound; }
 
     void put(const std::wstring& name, Tag* tag) {
-        tags[name] = tag->setName(name);
+        tag->setName(name);
+        tags[name] = std::unique_ptr<Tag>(tag);
     }
 
     void putByte(const std::wstring& name, uint8_t value) {
-        tags[name] = (new ByteTag(name, value));
+        tags[name] = std::make_unique<ByteTag>(name, value);
     }
 
     void putShort(const std::wstring& name, short value) {
-        tags[name] = (new ShortTag(name, value));
+        tags[name] = std::make_unique<ShortTag>(name, value);
     }
 
     void putInt(const std::wstring& name, int value) {
-        tags[name] = (new IntTag(name, value));
+        tags[name] = std::make_unique<IntTag>(name, value);
     }
 
     void putLong(const std::wstring& name, int64_t value) {
-        tags[name] = (new LongTag(name, value));
+        tags[name] = std::make_unique<LongTag>(name, value);
     }
 
     void putFloat(const std::wstring& name, float value) {
-        tags[name] = (new FloatTag(name, value));
+        tags[name] = std::make_unique<FloatTag>(name, value);
     }
 
     void putDouble(const std::wstring& name, double value) {
-        tags[name] = (new DoubleTag(name, value));
+        tags[name] = std::make_unique<DoubleTag>(name, value);
     }
 
     void putString(const std::wstring& name, const std::wstring& value) {
-        tags[name] = (new StringTag(name, value));
+        tags[name] = std::make_unique<StringTag>(name, value);
     }
 
     void putByteArray(const std::wstring& name, std::vector<uint8_t>& value) {
-        tags[name] = (new ByteArrayTag(name, value));
+        tags[name] = std::make_unique<ByteArrayTag>(name, value);
     }
 
     void putIntArray(const std::wstring& name, std::vector<int>& value) {
-        tags[name] = (new IntArrayTag(name, value));
+        tags[name] = std::make_unique<IntArrayTag>(name, value);
     }
 
     void putCompound(const std::wstring& name, CompoundTag* value) {
-        tags[name] = value->setName(std::wstring(name));
+        value->setName(name);
+        tags[name] = std::unique_ptr<Tag>(value);
     }
 
     void putBoolean(const std::wstring& name, bool val) {
@@ -111,7 +109,7 @@ public:
 
     Tag* get(const std::wstring& name) {
         auto it = tags.find(name);
-        if (it != tags.end()) return it->second;
+        if (it != tags.end()) return it->second.get();
         return nullptr;
     }
 
@@ -120,72 +118,87 @@ public:
     }
 
     uint8_t getByte(const std::wstring& name) {
-        if (tags.find(name) == tags.end()) return (uint8_t)0;
-        return ((ByteTag*)tags[name])->data;
+        auto it = tags.find(name);
+        if (it == tags.end()) return 0;
+        return static_cast<ByteTag*>(it->second.get())->data;
     }
 
     short getShort(const std::wstring& name) {
-        if (tags.find(name) == tags.end()) return (short)0;
-        return ((ShortTag*)tags[name])->data;
+        auto it = tags.find(name);
+        if (it == tags.end()) return 0;
+        return static_cast<ShortTag*>(it->second.get())->data;
     }
 
     int getInt(const std::wstring& name) {
-        if (tags.find(name) == tags.end()) return (int)0;
-        return ((IntTag*)tags[name])->data;
+        auto it = tags.find(name);
+        if (it == tags.end()) return 0;
+        return static_cast<IntTag*>(it->second.get())->data;
     }
 
     int64_t getLong(const std::wstring& name) {
-        if (tags.find(name) == tags.end()) return (int64_t)0;
-        return ((LongTag*)tags[name])->data;
+        auto it = tags.find(name);
+        if (it == tags.end()) return 0;
+        return static_cast<LongTag*>(it->second.get())->data;
     }
 
     float getFloat(const std::wstring& name) {
-        if (tags.find(name) == tags.end()) return (float)0;
-        return ((FloatTag*)tags[name])->data;
+        auto it = tags.find(name);
+        if (it == tags.end()) return 0;
+        return static_cast<FloatTag*>(it->second.get())->data;
     }
 
     double getDouble(const std::wstring& name) {
-        if (tags.find(name) == tags.end()) return (double)0;
-        return ((DoubleTag*)tags[name])->data;
+        auto it = tags.find(name);
+        if (it == tags.end()) return 0;
+        return static_cast<DoubleTag*>(it->second.get())->data;
     }
 
     std::wstring getString(const std::wstring& name) {
-        if (tags.find(name) == tags.end()) return std::wstring(L"");
-        return ((StringTag*)tags[name])->data;
+        auto it = tags.find(name);
+        if (it == tags.end()) return std::wstring(L"");
+        return static_cast<StringTag*>(it->second.get())->data;
     }
 
     std::vector<uint8_t> getByteArray(const std::wstring& name) {
-        if (tags.find(name) == tags.end()) return std::vector<uint8_t>();
-        return ((ByteArrayTag*)tags[name])->data;
+        auto it = tags.find(name);
+        if (it == tags.end()) return std::vector<uint8_t>();
+        return static_cast<ByteArrayTag*>(it->second.get())->data;
     }
 
     std::vector<int> getIntArray(const std::wstring& name) {
-        if (tags.find(name) == tags.end()) return std::vector<int>();
-        return ((IntArrayTag*)tags[name])->data;
+        auto it = tags.find(name);
+        if (it == tags.end()) return std::vector<int>();
+        return static_cast<IntArrayTag*>(it->second.get())->data;
     }
 
     CompoundTag* getCompound(const std::wstring& name) {
-        if (tags.find(name) == tags.end()) return new CompoundTag(name);
-        return (CompoundTag*)tags[name];
+        auto it = tags.find(name);
+        if (it == tags.end()) {
+            auto [it2, inserted] = tags.emplace(name, std::make_unique<CompoundTag>(name));
+            return static_cast<CompoundTag*>(it2->second.get());
+        }
+        return static_cast<CompoundTag*>(it->second.get());
     }
 
     ListTag<Tag>* getList(const std::wstring& name) {
-        if (tags.find(name) == tags.end()) return new ListTag<Tag>(name);
-        return (ListTag<Tag>*)tags[name];
+        auto it = tags.find(name);
+        if (it == tags.end()) {
+            auto [it2, inserted] = tags.emplace(name, std::make_unique<ListTag<Tag>>(name));
+            return static_cast<ListTag<Tag>*>(it2->second.get());
+        }
+        return static_cast<ListTag<Tag>*>(it->second.get());
     }
 
     bool getBoolean(const std::wstring& string) { return getByte(string) != 0; }
 
     void remove(const std::wstring& name) {
-        auto it = tags.find(name);
-        if (it != tags.end()) tags.erase(it);
-        // tags.remove(name);
+        tags.erase(name);
     }
 
     std::wstring toString() {
         static const int bufSize = 32;
         static wchar_t buf[bufSize];
-        swprintf(buf, bufSize, L"%d entries", tags.size());
+        swprintf(buf, bufSize, L"%zu entries", tags.size());
         return std::wstring(buf);
     }
 
@@ -211,19 +224,12 @@ public:
 
     bool isEmpty() { return tags.empty(); }
 
-    virtual ~CompoundTag() {
-        auto itEnd = tags.end();
-        for (auto it = tags.begin(); it != itEnd; it++) {
-            delete it->second;
-        }
-    }
+    virtual ~CompoundTag() = default;
 
     Tag* copy() {
         CompoundTag* tag = new CompoundTag(getName());
-
-        auto itEnd = tags.end();
-        for (auto it = tags.begin(); it != itEnd; it++) {
-            tag->put((wchar_t*)it->first.c_str(), it->second->copy());
+        for (auto& [key, value] : tags) {
+            tag->put(key, value->copy());
         }
         return tag;
     }
@@ -233,18 +239,14 @@ public:
             CompoundTag* o = (CompoundTag*)obj;
 
             if (tags.size() == o->tags.size()) {
-                bool equal = true;
-                auto itEnd = tags.end();
-                for (auto it = tags.begin(); it != itEnd; it++) {
-                    auto itFind = o->tags.find(it->first);
+                for (auto& [key, value] : tags) {
+                    auto itFind = o->tags.find(key);
                     if (itFind == o->tags.end() ||
-                        !it->second->equals(itFind->second)) {
-                        equal = false;
-                        break;
+                        !value->equals(itFind->second.get())) {
+                        return false;
                     }
                 }
-                return equal;
-                // return tags.entrySet().equals(o.tags.entrySet());
+                return true;
             }
         }
         return false;
diff --git a/minecraft/nbt/include/nbt/ListTag.h b/minecraft/nbt/include/nbt/ListTag.h
index c6b76d7ae..62a2e193e 100644
--- a/minecraft/nbt/include/nbt/ListTag.h
+++ b/minecraft/nbt/include/nbt/ListTag.h
@@ -1,12 +1,13 @@
 #pragma once
 #include "Tag.h"
 
+#include <memory>
 #include <vector>
 
 template <class T>
 class ListTag : public Tag {
 private:
-    std::vector<Tag*> list;
+    std::vector<std::unique_ptr<Tag>> list;
     uint8_t type;
 
 public:
@@ -15,15 +16,14 @@ public:
 
     void write(DataOutput* dos) {
         if (list.size() > 0)
-            type = (list[0])->getId();
+            type = list[0]->getId();
         else
             type = static_cast<uint8_t>(1);
 
         dos->writeByte(type);
         dos->writeInt((int)list.size());
 
-        auto itEnd = list.end();
-        for (auto it = list.begin(); it != itEnd; it++) (*it)->write(dos);
+        for (auto& tag : list) tag->write(dos);
     }
 
     void load(DataInput* dis, int tagDepth) {
@@ -39,9 +39,9 @@ public:
 
         list.clear();
         for (int i = 0; i < size; i++) {
-            Tag* tag = Tag::newTag(type, L"");
+            std::unique_ptr<Tag> tag(Tag::newTag(type, L""));
             tag->load(dis, tagDepth);
-            list.push_back(tag);
+            list.push_back(std::move(tag));
         }
     }
 
@@ -49,7 +49,7 @@ public:
 
     std::wstring toString() {
         static wchar_t buf[64];
-        swprintf(buf, 64, L"%d entries of type %ls", list.size(),
+        swprintf(buf, 64, L"%zu entries of type %ls", list.size(),
                  Tag::getTagName(type));
         return std::wstring(buf);
     }
@@ -62,9 +62,8 @@ public:
         char* newPrefix = new char[strlen(prefix) + 4];
         strcpy(newPrefix, prefix);
         strcat(newPrefix, "   ");
-        auto itEnd = list.end();
-        for (auto it = list.begin(); it != itEnd; it++) {
-            (*it)->print(newPrefix, out);
+        for (auto& tag : list) {
+            tag->print(newPrefix, out);
         }
         delete[] newPrefix;
         out << prefix << "}" << std::endl;
@@ -78,27 +77,20 @@ public:
         // other items that also use list tags and require equality checks to
         // work) considering we can't change the write/load functions.
         tag->setName(L"");
-        list.push_back(tag);
+        list.push_back(std::unique_ptr<Tag>(tag));
     }
 
-    T* get(int index) { return (T*)list[index]; }
+    T* get(int index) { return static_cast<T*>(list[index].get()); }
 
     int size() { return (int)list.size(); }
 
-    virtual ~ListTag() {
-        auto itEnd = list.end();
-        for (auto it = list.begin(); it != itEnd; it++) {
-            delete *it;
-        }
-    }
+    virtual ~ListTag() = default;
 
     virtual Tag* copy() {
         ListTag<T>* res = new ListTag<T>(getName());
         res->type = type;
-        auto itEnd = list.end();
-        for (auto it = list.begin(); it != itEnd; it++) {
-            T* copy = (T*)(*it)->copy();
-            res->list.push_back(copy);
+        for (auto& tag : list) {
+            res->list.push_back(std::unique_ptr<Tag>(tag->copy()));
         }
         return res;
     }
@@ -110,15 +102,13 @@ public:
                 bool equal = false;
                 if (list.size() == o->list.size()) {
                     equal = true;
-                    auto itEnd = list.end();
                     // 4J Stu - Pretty inefficient method, but I think we can
                     // live with it give how often it will happen, and the small
                     // sizes of the data sets
-                    for (auto it = list.begin(); it != itEnd; ++it) {
+                    for (auto& tag : list) {
                         bool thisMatches = false;
-                        for (auto it2 = o->list.begin(); it2 != o->list.end();
-                             ++it2) {
-                            if ((*it)->equals(*it2)) {
+                        for (auto& otherTag : o->list) {
+                            if (tag->equals(otherTag.get())) {
                                 thisMatches = true;
                                 break;
                             }
@@ -135,4 +125,4 @@ public:
         }
         return false;
     }
-};
\ No newline at end of file
+};