refactor(furvm): remove thing allocator

Refs: #62

furvm/include/furvm/context.hpp

@@ -7,9 +7,7 @@
 #include "furvm/handle.hpp"
 #include "furvm/module.hpp" // IWYU pragma: keep
 #include "furvm/thing.hpp"  // IWYU pragma: keep
-#include "furvm/thing_allocator.hpp"
 
-#include <cstddef>
 #include <utility>
 #include <vector>
 
@@ -22,8 +20,7 @@ public:
     /**
      * @brief Constructs a context.
      */
-    context()
-      : m_thingAllocator(m_thingArena) {}
+    context() {}
 
     ~context() = default;
 
@@ -70,21 +67,13 @@ public:
 
     const std::vector<executor>& executors() const { return m_executors; }
 public:
-    /**
-     * @brief Returns context's thing allocator.
-     *
-     * @return The thing allocator.
-     */
-    thing_allocator<std::byte> thing_alloc() const { return m_thingAllocator; }
-
     thing_type_store& tt_store() { return m_thingTypeStore; }
 private:
     handle_container<mod_h> m_modules;
     std::vector<executor>   m_executors;
 
-    furlang::arena             m_thingArena;
-    thing_allocator<std::byte> m_thingAllocator;
-    class thing_type_store     m_thingTypeStore;
+    furlang::arena         m_thingArena;
+    class thing_type_store m_thingTypeStore;
 };
 
 } // namespace furvm

furvm/include/furvm/fwd.hpp

@@ -140,11 +140,6 @@ using mod_id = std::string;
  */
 using mod_h = handle<mod, refcount_header<mod_id>>;
 
-// thing_allocator.hpp
-
-template <typename T>
-class thing_allocator;
-
 // thing.hpp
 
 /**
@@ -161,7 +156,7 @@ using thing_type_id = std::uint32_t;
  *
  * A stack element. Think of it like of a value in C++ or I guess a class in java.
  */
-template <template <typename> typename Allocator = thing_allocator>
+template <template <typename> typename Allocator = std::allocator>
 class thing;
 
 /**

furvm/include/furvm/thing.hpp

@@ -5,7 +5,6 @@
 #include "furlang/utility/hash.hpp"
 #include "furvm/exceptions.hpp"
 #include "furvm/fwd.hpp"
-#include "furvm/thing_allocator.hpp" // IWYU pragma: keep
 
 #include <algorithm>
 #include <cstddef>

furvm/include/furvm/thing_allocator.hpp

@@ -1,113 +0,0 @@
-#ifndef FURVM_THING_ALLOCATOR_HPP
-#define FURVM_THING_ALLOCATOR_HPP
-
-#include "furlang/arena.hpp"
-
-#include <vector>
-
-namespace furvm {
-
-template <typename T>
-class thing_allocator {
-    template <typename>
-    friend class thing_allocator;
-
-    using dead_things = std::vector<std::pair<T*, std::size_t>>;
-public:
-    using value_type = T; /**< Value type. */
-public:
-    thing_allocator() = default;
-
-    /**
-     * @brief Constructs a thing allocator.
-     *
-     * @param arena Base arena allocator.
-     */
-    explicit thing_allocator(furlang::arena& arena) noexcept
-      : m_arena(&arena), m_deadThings(std::make_shared<dead_things>()) {}
-
-    /**
-     * @brief Move constructor.
-     */
-    template <typename U>
-    thing_allocator(thing_allocator<U>&& other) noexcept
-      : m_arena(std::move(other.m_arena)), m_deadThings(std::move(other.m_deadThings)) {}
-
-    /**
-     * @brief Move constructor.
-     */
-    template <typename U>
-    thing_allocator& operator=(thing_allocator<U>&& other) noexcept {
-        if (this == &other) return *this;
-        m_arena      = std::move(other.m_arena);
-        m_deadThings = std::move(other.m_deadThings);
-        return *this;
-    }
-
-    /**
-     * @brief Copy constructor.
-     */
-    template <typename U>
-    thing_allocator(const thing_allocator<U>& other) noexcept
-      : m_arena(other.m_arena), m_deadThings(other.m_deadThings) {}
-
-    /**
-     * @brief Copy constructor.
-     */
-    template <typename U>
-    thing_allocator& operator=(const thing_allocator<U>& other) noexcept {
-        if (this == &other) return *this;
-        m_arena      = other.m_arena;
-        m_deadThings = other.m_deadThings;
-        return *this;
-    }
-public:
-    /**
-     * @brief Returns a free chunk of memory.
-     *
-     * @param count Count of the things that must fit inside the chunk.
-     * @return The chunk.
-     */
-    [[nodiscard]] T* allocate(std::size_t count = 1) {
-        for (auto it = m_deadThings->begin(); it != m_deadThings->end(); ++it) {
-            if (it->second != count) continue;
-            T* data = it->first;
-            m_deadThings->erase(it);
-            return data;
-        }
-        return m_arena->allocate<T>(count);
-    }
-
-    /**
-     * @brief Recycles the pointer.
-     */
-    void deallocate(T* ptr, std::size_t count) noexcept { m_deadThings->emplace_back(ptr, count); }
-public:
-    /**
-     * @brief Compares two thing allocators for equality.
-     *
-     * @return true if the two things are equal.
-     */
-    template <typename U>
-    bool operator==(const thing_allocator<U>& other) const noexcept {
-        return m_arena == other.m_arena && m_deadThings == other.m_deadThings;
-    }
-
-    /**
-     * @brief Compares two thing allocators for inequality.
-     *
-     * @return true if the two things are not equal.
-     */
-    template <typename U>
-    bool operator!=(const thing_allocator<U>& other) const noexcept {
-        return m_arena != other.m_arena || m_deadThings != other.m_deadThings;
-    }
-private:
-    furlang::arena* m_arena = nullptr;
-
-    std::shared_ptr<dead_things> m_deadThings;
-};
-
-} // namespace furvm
-
-#endif // FURVM_THING_ALLOCATOR_HPP