--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CSP2/CSP2_env/env-d9b9114564458d9d-741b3de822f2aaca6c6caa4325c4afce/include/kj/memory.h	Tue Mar 18 17:55:14 2025 -0400
@@ -0,0 +1,797 @@
+// Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors
+// Licensed under the MIT License:
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+#pragma once
+
+#include "common.h"
+
+KJ_BEGIN_HEADER
+
+namespace kj {
+
+template <typename T>
+inline constexpr bool _kj_internal_isPolymorphic(T*) {
+  // If you get a compiler error here complaining that T is incomplete, it's because you are trying
+  // to use kj::Own<T> with a type that has only been forward-declared. Since KJ doesn't know if
+  // the type might be involved in inheritance (especially multiple inheritance), it doesn't know
+  // how to correctly call the disposer to destroy the type, since the object's true memory address
+  // may differ from the address used to point to a superclass.
+  //
+  // However, if you know for sure that T is NOT polymorphic (i.e. it doesn't have a vtable and
+  // isn't involved in inheritance), then you can use KJ_DECLARE_NON_POLYMORPHIC(T) to declare this
+  // to KJ without actually completing the type. Place this macro invocation either in the global
+  // scope, or in the same namespace as T is defined.
+  return __is_polymorphic(T);
+}
+
+#define KJ_DECLARE_NON_POLYMORPHIC(...) \
+  inline constexpr bool _kj_internal_isPolymorphic(__VA_ARGS__*) { \
+    return false; \
+  }
+// If you want to use kj::Own<T> for an incomplete type T that you know is not polymorphic, then
+// write `KJ_DECLARE_NON_POLYMORPHIC(T)` either at the global scope or in the same namespace as
+// T is declared.
+//
+// This also works for templates, e.g.:
+//
+//     template <typename X, typename Y>
+//     struct MyType;
+//     template <typename X, typename Y>
+//     KJ_DECLARE_NON_POLYMORPHIC(MyType<X, Y>)
+
+namespace _ {  // private
+
+template <typename T> struct RefOrVoid_ { typedef T& Type; };
+template <> struct RefOrVoid_<void> { typedef void Type; };
+template <> struct RefOrVoid_<const void> { typedef void Type; };
+
+template <typename T>
+using RefOrVoid = typename RefOrVoid_<T>::Type;
+// Evaluates to T&, unless T is `void`, in which case evaluates to `void`.
+//
+// This is a hack needed to avoid defining Own<void> as a totally separate class.
+
+template <typename T, bool isPolymorphic = _kj_internal_isPolymorphic((T*)nullptr)>
+struct CastToVoid_;
+
+template <typename T>
+struct CastToVoid_<T, false> {
+  static void* apply(T* ptr) {
+    return static_cast<void*>(ptr);
+  }
+  static const void* applyConst(T* ptr) {
+    const T* cptr = ptr;
+    return static_cast<const void*>(cptr);
+  }
+};
+
+template <typename T>
+struct CastToVoid_<T, true> {
+  static void* apply(T* ptr) {
+    return dynamic_cast<void*>(ptr);
+  }
+  static const void* applyConst(T* ptr) {
+    const T* cptr = ptr;
+    return dynamic_cast<const void*>(cptr);
+  }
+};
+
+template <typename T>
+void* castToVoid(T* ptr) {
+  return CastToVoid_<T>::apply(ptr);
+}
+
+template <typename T>
+const void* castToConstVoid(T* ptr) {
+  return CastToVoid_<T>::applyConst(ptr);
+}
+
+}  // namespace _ (private)
+
+// =======================================================================================
+// Disposer -- Implementation details.
+
+class Disposer {
+  // Abstract interface for a thing that "disposes" of objects, where "disposing" usually means
+  // calling the destructor followed by freeing the underlying memory.  `Own<T>` encapsulates an
+  // object pointer with corresponding Disposer.
+  //
+  // Few developers will ever touch this interface.  It is primarily useful for those implementing
+  // custom memory allocators.
+
+protected:
+  // Do not declare a destructor, as doing so will force a global initializer for each HeapDisposer
+  // instance.  Eww!
+
+  virtual void disposeImpl(void* pointer) const = 0;
+  // Disposes of the object, given a pointer to the beginning of the object.  If the object is
+  // polymorphic, this pointer is determined by dynamic_cast<void*>().  For non-polymorphic types,
+  // Own<T> does not allow any casting, so the pointer exactly matches the original one given to
+  // Own<T>.
+
+public:
+
+  template <typename T>
+  void dispose(T* object) const;
+  // Helper wrapper around disposeImpl().
+  //
+  // If T is polymorphic, calls `disposeImpl(dynamic_cast<void*>(object))`, otherwise calls
+  // `disposeImpl(implicitCast<void*>(object))`.
+  //
+  // Callers must not call dispose() on the same pointer twice, even if the first call throws
+  // an exception.
+
+private:
+  template <typename T, bool polymorphic = _kj_internal_isPolymorphic((T*)nullptr)>
+  struct Dispose_;
+};
+
+template <typename T>
+class DestructorOnlyDisposer: public Disposer {
+  // A disposer that merely calls the type's destructor and nothing else.
+
+public:
+  static const DestructorOnlyDisposer instance;
+
+  void disposeImpl(void* pointer) const override {
+    reinterpret_cast<T*>(pointer)->~T();
+  }
+};
+
+template <typename T>
+const DestructorOnlyDisposer<T> DestructorOnlyDisposer<T>::instance = DestructorOnlyDisposer<T>();
+
+class NullDisposer: public Disposer {
+  // A disposer that does nothing.
+
+public:
+  static const NullDisposer instance;
+
+  void disposeImpl(void* pointer) const override {}
+};
+
+// =======================================================================================
+// Own<T> -- An owned pointer.
+
+template <typename T, typename StaticDisposer = decltype(nullptr)>
+class Own;
+
+template <typename T>
+class Own<T, decltype(nullptr)> {
+  // A transferrable title to a T.  When an Own<T> goes out of scope, the object's Disposer is
+  // called to dispose of it.  An Own<T> can be efficiently passed by move, without relocating the
+  // underlying object; this transfers ownership.
+  //
+  // This is much like std::unique_ptr, except:
+  // - You cannot release().  An owned object is not necessarily allocated with new (see next
+  //   point), so it would be hard to use release() correctly.
+  // - The deleter is made polymorphic by virtual call rather than by template.  This is much
+  //   more powerful -- it allows the use of custom allocators, freelists, etc.  This could
+  //   _almost_ be accomplished with unique_ptr by forcing everyone to use something like
+  //   std::unique_ptr<T, kj::Deleter>, except that things get hairy in the presence of multiple
+  //   inheritance and upcasting, and anyway if you force everyone to use a custom deleter
+  //   then you've lost any benefit to interoperating with the "standard" unique_ptr.
+
+public:
+  KJ_DISALLOW_COPY(Own);
+  inline Own(): disposer(nullptr), ptr(nullptr) {}
+  inline Own(Own&& other) noexcept
+      : disposer(other.disposer), ptr(other.ptr) { other.ptr = nullptr; }
+  inline Own(Own<RemoveConstOrDisable<T>>&& other) noexcept
+      : disposer(other.disposer), ptr(other.ptr) { other.ptr = nullptr; }
+  template <typename U, typename = EnableIf<canConvert<U*, T*>()>>
+  inline Own(Own<U>&& other) noexcept
+      : disposer(other.disposer), ptr(cast(other.ptr)) {
+    other.ptr = nullptr;
+  }
+  template <typename U, typename StaticDisposer, typename = EnableIf<canConvert<U*, T*>()>>
+  inline Own(Own<U, StaticDisposer>&& other) noexcept;
+  // Convert statically-disposed Own to dynamically-disposed Own.
+  inline Own(T* ptr, const Disposer& disposer) noexcept: disposer(&disposer), ptr(ptr) {}
+
+  ~Own() noexcept(false) { dispose(); }
+
+  inline Own& operator=(Own&& other) {
+    // Move-assignnment operator.
+
+    // Careful, this might own `other`.  Therefore we have to transfer the pointers first, then
+    // dispose.
+    const Disposer* disposerCopy = disposer;
+    T* ptrCopy = ptr;
+    disposer = other.disposer;
+    ptr = other.ptr;
+    other.ptr = nullptr;
+    if (ptrCopy != nullptr) {
+      disposerCopy->dispose(const_cast<RemoveConst<T>*>(ptrCopy));
+    }
+    return *this;
+  }
+
+  inline Own& operator=(decltype(nullptr)) {
+    dispose();
+    return *this;
+  }
+
+  template <typename... Attachments>
+  Own<T> attach(Attachments&&... attachments) KJ_WARN_UNUSED_RESULT;
+  // Returns an Own<T> which points to the same object but which also ensures that all values
+  // passed to `attachments` remain alive until after this object is destroyed. Normally
+  // `attachments` are other Own<?>s pointing to objects that this one depends on.
+  //
+  // Note that attachments will eventually be destroyed in the order they are listed. Hence,
+  // foo.attach(bar, baz) is equivalent to (but more efficient than) foo.attach(bar).attach(baz).
+
+  template <typename U>
+  Own<U> downcast() {
+    // Downcast the pointer to Own<U>, destroying the original pointer.  If this pointer does not
+    // actually point at an instance of U, the results are undefined (throws an exception in debug
+    // mode if RTTI is enabled, otherwise you're on your own).
+
+    Own<U> result;
+    if (ptr != nullptr) {
+      result.ptr = &kj::downcast<U>(*ptr);
+      result.disposer = disposer;
+      ptr = nullptr;
+    }
+    return result;
+  }
+
+#define NULLCHECK KJ_IREQUIRE(ptr != nullptr, "null Own<> dereference")
+  inline T* operator->() { NULLCHECK; return ptr; }
+  inline const T* operator->() const { NULLCHECK; return ptr; }
+  inline _::RefOrVoid<T> operator*() { NULLCHECK; return *ptr; }
+  inline _::RefOrVoid<const T> operator*() const { NULLCHECK; return *ptr; }
+#undef NULLCHECK
+  inline T* get() { return ptr; }
+  inline const T* get() const { return ptr; }
+  inline operator T*() { return ptr; }
+  inline operator const T*() const { return ptr; }
+
+private:
+  const Disposer* disposer;  // Only valid if ptr != nullptr.
+  T* ptr;
+
+  inline explicit Own(decltype(nullptr)): disposer(nullptr), ptr(nullptr) {}
+
+  inline bool operator==(decltype(nullptr)) { return ptr == nullptr; }
+  inline bool operator!=(decltype(nullptr)) { return ptr != nullptr; }
+  // Only called by Maybe<Own<T>>.
+
+  inline void dispose() {
+    // Make sure that if an exception is thrown, we are left with a null ptr, so we won't possibly
+    // dispose again.
+    T* ptrCopy = ptr;
+    if (ptrCopy != nullptr) {
+      ptr = nullptr;
+      disposer->dispose(const_cast<RemoveConst<T>*>(ptrCopy));
+    }
+  }
+
+  template <typename U>
+  static inline T* cast(U* ptr) {
+    static_assert(_kj_internal_isPolymorphic((T*)nullptr),
+        "Casting owned pointers requires that the target type is polymorphic.");
+    return ptr;
+  }
+
+  template <typename, typename>
+  friend class Own;
+  friend class Maybe<Own<T>>;
+};
+
+template <>
+template <typename U>
+inline void* Own<void>::cast(U* ptr) {
+  return _::castToVoid(ptr);
+}
+
+template <>
+template <typename U>
+inline const void* Own<const void>::cast(U* ptr) {
+  return _::castToConstVoid(ptr);
+}
+
+template <typename T, typename StaticDisposer>
+class Own {
+  // If a `StaticDisposer` is specified (which is not the norm), then the object will be deleted
+  // by calling StaticDisposer::dispose(pointer). The pointer passed to `dispose()` could be a
+  // superclass of `T`, if the pointer has been upcast.
+  //
+  // This type can be useful for micro-optimization, if you've found that you are doing excessive
+  // heap allocations to the point where the virtual call on destruction is costing non-negligible
+  // resources. You should avoid this unless you have a specific need, because it precludes a lot
+  // of power.
+
+public:
+  KJ_DISALLOW_COPY(Own);
+  inline Own(): ptr(nullptr) {}
+  inline Own(Own&& other) noexcept
+      : ptr(other.ptr) { other.ptr = nullptr; }
+  inline Own(Own<RemoveConstOrDisable<T>, StaticDisposer>&& other) noexcept
+      : ptr(other.ptr) { other.ptr = nullptr; }
+  template <typename U, typename = EnableIf<canConvert<U*, T*>()>>
+  inline Own(Own<U, StaticDisposer>&& other) noexcept
+      : ptr(cast(other.ptr)) {
+    other.ptr = nullptr;
+  }
+  inline explicit Own(T* ptr) noexcept: ptr(ptr) {}
+
+  ~Own() noexcept(false) { dispose(); }
+
+  inline Own& operator=(Own&& other) {
+    // Move-assignnment operator.
+
+    // Careful, this might own `other`.  Therefore we have to transfer the pointers first, then
+    // dispose.
+    T* ptrCopy = ptr;
+    ptr = other.ptr;
+    other.ptr = nullptr;
+    if (ptrCopy != nullptr) {
+      StaticDisposer::dispose(ptrCopy);
+    }
+    return *this;
+  }
+
+  inline Own& operator=(decltype(nullptr)) {
+    dispose();
+    return *this;
+  }
+
+  template <typename U>
+  Own<U, StaticDisposer> downcast() {
+    // Downcast the pointer to Own<U>, destroying the original pointer.  If this pointer does not
+    // actually point at an instance of U, the results are undefined (throws an exception in debug
+    // mode if RTTI is enabled, otherwise you're on your own).
+
+    Own<U, StaticDisposer> result;
+    if (ptr != nullptr) {
+      result.ptr = &kj::downcast<U>(*ptr);
+      ptr = nullptr;
+    }
+    return result;
+  }
+
+#define NULLCHECK KJ_IREQUIRE(ptr != nullptr, "null Own<> dereference")
+  inline T* operator->() { NULLCHECK; return ptr; }
+  inline const T* operator->() const { NULLCHECK; return ptr; }
+  inline _::RefOrVoid<T> operator*() { NULLCHECK; return *ptr; }
+  inline _::RefOrVoid<const T> operator*() const { NULLCHECK; return *ptr; }
+#undef NULLCHECK
+  inline T* get() { return ptr; }
+  inline const T* get() const { return ptr; }
+  inline operator T*() { return ptr; }
+  inline operator const T*() const { return ptr; }
+
+private:
+  T* ptr;
+
+  inline explicit Own(decltype(nullptr)): ptr(nullptr) {}
+
+  inline bool operator==(decltype(nullptr)) { return ptr == nullptr; }
+  inline bool operator!=(decltype(nullptr)) { return ptr != nullptr; }
+  // Only called by Maybe<Own<T>>.
+
+  inline void dispose() {
+    // Make sure that if an exception is thrown, we are left with a null ptr, so we won't possibly
+    // dispose again.
+    T* ptrCopy = ptr;
+    if (ptrCopy != nullptr) {
+      ptr = nullptr;
+      StaticDisposer::dispose(ptrCopy);
+    }
+  }
+
+  template <typename U>
+  static inline T* cast(U* ptr) {
+    return ptr;
+  }
+
+  template <typename, typename>
+  friend class Own;
+  friend class Maybe<Own<T, StaticDisposer>>;
+};
+
+namespace _ {  // private
+
+template <typename T, typename D>
+class OwnOwn {
+public:
+  inline OwnOwn(Own<T, D>&& value) noexcept: value(kj::mv(value)) {}
+
+  inline Own<T, D>& operator*() & { return value; }
+  inline const Own<T, D>& operator*() const & { return value; }
+  inline Own<T, D>&& operator*() && { return kj::mv(value); }
+  inline const Own<T, D>&& operator*() const && { return kj::mv(value); }
+  inline Own<T, D>* operator->() { return &value; }
+  inline const Own<T, D>* operator->() const { return &value; }
+  inline operator Own<T, D>*() { return value ? &value : nullptr; }
+  inline operator const Own<T, D>*() const { return value ? &value : nullptr; }
+
+private:
+  Own<T, D> value;
+};
+
+template <typename T, typename D>
+OwnOwn<T, D> readMaybe(Maybe<Own<T, D>>&& maybe) { return OwnOwn<T, D>(kj::mv(maybe.ptr)); }
+template <typename T, typename D>
+Own<T, D>* readMaybe(Maybe<Own<T, D>>& maybe) { return maybe.ptr ? &maybe.ptr : nullptr; }
+template <typename T, typename D>
+const Own<T, D>* readMaybe(const Maybe<Own<T, D>>& maybe) {
+  return maybe.ptr ? &maybe.ptr : nullptr;
+}
+
+}  // namespace _ (private)
+
+template <typename T, typename D>
+class Maybe<Own<T, D>> {
+public:
+  inline Maybe(): ptr(nullptr) {}
+  inline Maybe(Own<T, D>&& t) noexcept: ptr(kj::mv(t)) {}
+  inline Maybe(Maybe&& other) noexcept: ptr(kj::mv(other.ptr)) {}
+
+  template <typename U>
+  inline Maybe(Maybe<Own<U, D>>&& other): ptr(mv(other.ptr)) {}
+  template <typename U>
+  inline Maybe(Own<U, D>&& other): ptr(mv(other)) {}
+
+  inline Maybe(decltype(nullptr)) noexcept: ptr(nullptr) {}
+
+  inline Own<T, D>& emplace(Own<T, D> value) {
+    // Assign the Maybe to the given value and return the content. This avoids the need to do a
+    // KJ_ASSERT_NONNULL() immediately after setting the Maybe just to read it back again.
+    ptr = kj::mv(value);
+    return ptr;
+  }
+
+  template <typename U = T>
+  inline operator NoInfer<Maybe<U&>>() { return ptr.get(); }
+  template <typename U = T>
+  inline operator NoInfer<Maybe<const U&>>() const { return ptr.get(); }
+  // Implicit conversion to `Maybe<U&>`. The weird templating is to make sure that
+  // `Maybe<Own<void>>` can be instantiated with the compiler complaining about forming references
+  // to void -- the use of templates here will cause SFINAE to kick in and hide these, whereas if
+  // they are not templates then SFINAE isn't applied and so they are considered errors.
+
+  inline Maybe& operator=(Maybe&& other) { ptr = kj::mv(other.ptr); return *this; }
+
+  inline bool operator==(decltype(nullptr)) const { return ptr == nullptr; }
+  inline bool operator!=(decltype(nullptr)) const { return ptr != nullptr; }
+
+  Own<T, D>& orDefault(Own<T, D>& defaultValue) {
+    if (ptr == nullptr) {
+      return defaultValue;
+    } else {
+      return ptr;
+    }
+  }
+  const Own<T, D>& orDefault(const Own<T, D>& defaultValue) const {
+    if (ptr == nullptr) {
+      return defaultValue;
+    } else {
+      return ptr;
+    }
+  }
+
+  template <typename F,
+      typename Result = decltype(instance<bool>() ? instance<Own<T, D>>() : instance<F>()())>
+  Result orDefault(F&& lazyDefaultValue) && {
+    if (ptr == nullptr) {
+      return lazyDefaultValue();
+    } else {
+      return kj::mv(ptr);
+    }
+  }
+
+  template <typename Func>
+  auto map(Func&& f) & -> Maybe<decltype(f(instance<Own<T, D>&>()))> {
+    if (ptr == nullptr) {
+      return nullptr;
+    } else {
+      return f(ptr);
+    }
+  }
+
+  template <typename Func>
+  auto map(Func&& f) const & -> Maybe<decltype(f(instance<const Own<T, D>&>()))> {
+    if (ptr == nullptr) {
+      return nullptr;
+    } else {
+      return f(ptr);
+    }
+  }
+
+  template <typename Func>
+  auto map(Func&& f) && -> Maybe<decltype(f(instance<Own<T, D>&&>()))> {
+    if (ptr == nullptr) {
+      return nullptr;
+    } else {
+      return f(kj::mv(ptr));
+    }
+  }
+
+  template <typename Func>
+  auto map(Func&& f) const && -> Maybe<decltype(f(instance<const Own<T, D>&&>()))> {
+    if (ptr == nullptr) {
+      return nullptr;
+    } else {
+      return f(kj::mv(ptr));
+    }
+  }
+
+private:
+  Own<T, D> ptr;
+
+  template <typename U>
+  friend class Maybe;
+  template <typename U, typename D2>
+  friend _::OwnOwn<U, D2> _::readMaybe(Maybe<Own<U, D2>>&& maybe);
+  template <typename U, typename D2>
+  friend Own<U, D2>* _::readMaybe(Maybe<Own<U, D2>>& maybe);
+  template <typename U, typename D2>
+  friend const Own<U, D2>* _::readMaybe(const Maybe<Own<U, D2>>& maybe);
+};
+
+namespace _ {  // private
+
+template <typename T>
+class HeapDisposer final: public Disposer {
+public:
+  virtual void disposeImpl(void* pointer) const override { delete reinterpret_cast<T*>(pointer); }
+
+  static const HeapDisposer instance;
+};
+
+#if _MSC_VER && _MSC_VER < 1920 && !defined(__clang__)
+template <typename T>
+__declspec(selectany) const HeapDisposer<T> HeapDisposer<T>::instance = HeapDisposer<T>();
+// On MSVC 2017 we suddenly started seeing a linker error on one specific specialization of
+// `HeapDisposer::instance` when seemingly-unrelated code was modified. Explicitly specifying
+// `__declspec(selectany)` seems to fix it. But why? Shouldn't template members have `selectany`
+// behavior by default? We don't know. It works and we're moving on.
+#else
+template <typename T>
+const HeapDisposer<T> HeapDisposer<T>::instance = HeapDisposer<T>();
+#endif
+
+#if KJ_CPP_STD >= 202002L
+template <typename T, void(*F)(T*)>
+class CustomDisposer: public Disposer {
+public:
+  void disposeImpl(void* pointer) const override {
+    (*F)(reinterpret_cast<T*>(pointer));
+  }
+};
+
+template <typename T, void(*F)(T*)>
+static constexpr CustomDisposer<T, F> CUSTOM_DISPOSER_INSTANCE {};
+#else
+template <typename T, void(*F)(T*)>
+class CustomDisposer: public Disposer {
+public:
+  static const CustomDisposer instance;
+
+  void disposeImpl(void* pointer) const override {
+    (*F)(reinterpret_cast<T*>(pointer));
+  }
+};
+
+template <typename T, void(*F)(T*)>
+const CustomDisposer<T, F> CustomDisposer<T, F>::instance = CustomDisposer<T, F>();
+#endif
+
+}  // namespace _ (private)
+
+template <typename T, typename... Params>
+Own<T> heap(Params&&... params) {
+  // heap<T>(...) allocates a T on the heap, forwarding the parameters to its constructor.  The
+  // exact heap implementation is unspecified -- for now it is operator new, but you should not
+  // assume this.  (Since we know the object size at delete time, we could actually implement an
+  // allocator that is more efficient than operator new.)
+
+  return Own<T>(new T(kj::fwd<Params>(params)...), _::HeapDisposer<T>::instance);
+}
+
+template <typename T>
+Own<Decay<T>> heap(T&& orig) {
+  // Allocate a copy (or move) of the argument on the heap.
+  //
+  // The purpose of this overload is to allow you to omit the template parameter as there is only
+  // one argument and the purpose is to copy it.
+
+  typedef Decay<T> T2;
+  return Own<T2>(new T2(kj::fwd<T>(orig)), _::HeapDisposer<T2>::instance);
+}
+
+#if KJ_CPP_STD > 201402L
+#if KJ_CPP_STD < 202002L
+template <auto F, typename T>
+Own<T> disposeWith(T* ptr) {
+  // Associate a pre-allocated raw pointer with a corresponding disposal function.
+  // The first template parameter should be a function pointer e.g. disposeWith<freeInt>(new int(0)).
+
+  return Own<T>(ptr, _::CustomDisposer<T, F>::instance);
+}
+#else
+template <auto F, typename T>
+Own<T> disposeWith(T* ptr) {
+  // Associate a pre-allocated raw pointer with a corresponding disposal function.
+  // The first template parameter should be a function pointer e.g. disposeWith<freeInt>(new int(0)).
+
+  return Own<T>(ptr, _::CUSTOM_DISPOSER_INSTANCE<T, F>);
+}
+#endif
+#endif
+
+template <typename T, typename... Attachments>
+Own<Decay<T>> attachVal(T&& value, Attachments&&... attachments);
+// Returns an Own<T> that takes ownership of `value` and `attachments`, and points to `value`.
+//
+// This is equivalent to heap(value).attach(attachments), but only does one allocation rather than
+// two.
+
+template <typename T, typename... Attachments>
+Own<T> attachRef(T& value, Attachments&&... attachments);
+// Like attach() but `value` is not moved; the resulting Own<T> points to its existing location.
+// This is preferred if `value` is already owned by one of `attachments`.
+//
+// This is equivalent to Own<T>(&value, kj::NullDisposer::instance).attach(attachments), but
+// is easier to write and allocates slightly less memory.
+
+// =======================================================================================
+// SpaceFor<T> -- assists in manual allocation
+
+template <typename T>
+class SpaceFor {
+  // A class which has the same size and alignment as T but does not call its constructor or
+  // destructor automatically.  Instead, call construct() to construct a T in the space, which
+  // returns an Own<T> which will take care of calling T's destructor later.
+
+public:
+  inline SpaceFor() {}
+  inline ~SpaceFor() {}
+
+  template <typename... Params>
+  Own<T> construct(Params&&... params) {
+    ctor(value, kj::fwd<Params>(params)...);
+    return Own<T>(&value, DestructorOnlyDisposer<T>::instance);
+  }
+
+private:
+  union {
+    T value;
+  };
+};
+
+// =======================================================================================
+// Inline implementation details
+
+template <typename T>
+struct Disposer::Dispose_<T, true> {
+  static void dispose(T* object, const Disposer& disposer) {
+    // Note that dynamic_cast<void*> does not require RTTI to be enabled, because the offset to
+    // the top of the object is in the vtable -- as it obviously needs to be to correctly implement
+    // operator delete.
+    disposer.disposeImpl(dynamic_cast<void*>(object));
+  }
+};
+template <typename T>
+struct Disposer::Dispose_<T, false> {
+  static void dispose(T* object, const Disposer& disposer) {
+    disposer.disposeImpl(static_cast<void*>(object));
+  }
+};
+
+template <typename T>
+void Disposer::dispose(T* object) const {
+  Dispose_<T>::dispose(object, *this);
+}
+
+namespace _ {  // private
+
+template <typename... T>
+struct OwnedBundle;
+
+template <>
+struct OwnedBundle<> {};
+
+template <typename First, typename... Rest>
+struct OwnedBundle<First, Rest...>: public OwnedBundle<Rest...> {
+  OwnedBundle(First&& first, Rest&&... rest)
+      : OwnedBundle<Rest...>(kj::fwd<Rest>(rest)...), first(kj::fwd<First>(first)) {}
+
+  // Note that it's intentional that `first` is destroyed before `rest`. This way, doing
+  // ptr.attach(foo, bar, baz) is equivalent to ptr.attach(foo).attach(bar).attach(baz) in terms
+  // of destruction order (although the former does fewer allocations).
+  Decay<First> first;
+};
+
+template <typename... T>
+struct DisposableOwnedBundle final: public Disposer, public OwnedBundle<T...> {
+  DisposableOwnedBundle(T&&... values): OwnedBundle<T...>(kj::fwd<T>(values)...) {}
+  void disposeImpl(void* pointer) const override { delete this; }
+};
+
+template <typename T, typename StaticDisposer>
+class StaticDisposerAdapter final: public Disposer {
+  // Adapts a static disposer to be called dynamically.
+public:
+  virtual void disposeImpl(void* pointer) const override {
+    StaticDisposer::dispose(reinterpret_cast<T*>(pointer));
+  }
+
+  static const StaticDisposerAdapter instance;
+};
+
+template <typename T, typename D>
+const StaticDisposerAdapter<T, D> StaticDisposerAdapter<T, D>::instance =
+    StaticDisposerAdapter<T, D>();
+
+}  // namespace _ (private)
+
+template <typename T>
+template <typename... Attachments>
+Own<T> Own<T>::attach(Attachments&&... attachments) {
+  T* ptrCopy = ptr;
+
+  KJ_IREQUIRE(ptrCopy != nullptr, "cannot attach to null pointer");
+
+  // HACK: If someone accidentally calls .attach() on a null pointer in opt mode, try our best to
+  //   accomplish reasonable behavior: We turn the pointer non-null but still invalid, so that the
+  //   disposer will still be called when the pointer goes out of scope.
+  if (ptrCopy == nullptr) ptrCopy = reinterpret_cast<T*>(1);
+
+  auto bundle = new _::DisposableOwnedBundle<Own<T>, Attachments...>(
+      kj::mv(*this), kj::fwd<Attachments>(attachments)...);
+  return Own<T>(ptrCopy, *bundle);
+}
+
+template <typename T, typename... Attachments>
+Own<T> attachRef(T& value, Attachments&&... attachments) {
+  auto bundle = new _::DisposableOwnedBundle<Attachments...>(kj::fwd<Attachments>(attachments)...);
+  return Own<T>(&value, *bundle);
+}
+
+template <typename T, typename... Attachments>
+Own<Decay<T>> attachVal(T&& value, Attachments&&... attachments) {
+  auto bundle = new _::DisposableOwnedBundle<T, Attachments...>(
+      kj::fwd<T>(value), kj::fwd<Attachments>(attachments)...);
+  return Own<Decay<T>>(&bundle->first, *bundle);
+}
+
+template <typename T>
+template <typename U, typename StaticDisposer, typename>
+inline Own<T>::Own(Own<U, StaticDisposer>&& other) noexcept
+    : ptr(cast(other.ptr)) {
+  if (_::castToVoid(other.ptr) != reinterpret_cast<void*>(other.ptr)) {
+    // Oh dangit, there's some sort of multiple inheritance going on and `StaticDisposerAdapter`
+    // won't actually work because it'll receive a pointer pointing to the top of the object, which
+    // isn't exactly the same as the `U*` pointer it wants. We have no choice but to allocate
+    // a dynamic disposer here.
+    disposer = new _::DisposableOwnedBundle<Own<U, StaticDisposer>>(kj::mv(other));
+  } else {
+    disposer = &_::StaticDisposerAdapter<U, StaticDisposer>::instance;
+    other.ptr = nullptr;
+  }
+}
+
+}  // namespace kj
+
+KJ_END_HEADER