Some work on maybe_uninit & option

1 files changed, 30 insertions, 11 deletions

diff --git a/asl/maybe_uninit.hpp b/asl/maybe_uninit.hpp
index ffbbb1c..19351d5 100644
--- a/asl/maybe_uninit.hpp
+++ b/asl/maybe_uninit.hpp
@@ -1,42 +1,61 @@
 #pragma once

 

-#include "asl/annotations.hpp"

 #include "asl/layout.hpp"

 #include "asl/memory.hpp"

 #include "asl/meta.hpp"

+#include "asl/utility.hpp"

 

 namespace asl

 {

 

 template<is_object T>

-class alignas(align_of<T>) maybe_uninit

+class maybe_uninit

 {

-    char m_storage[size_of<T>];

+    union

+    {

+        alignas(align_of<T>) char m_storage[size_of<T>];

+        T m_value;

+    };

 

 public:

-    constexpr void* uninit_ptr() const { return m_storage; }

+    constexpr maybe_uninit() {} // NOLINT(*-member-init)

+    

+    maybe_uninit(const maybe_uninit&) = delete;

+    maybe_uninit(maybe_uninit&&) = delete;

+

+    maybe_uninit& operator=(const maybe_uninit&) = delete;

+    maybe_uninit& operator=(maybe_uninit&&) = delete;

+    

+    constexpr ~maybe_uninit() = default;

+    constexpr ~maybe_uninit() requires (!trivially_destructible<T>) {}

+    

+    constexpr void*       uninit_ptr() && = delete;

+    constexpr const void* uninit_ptr() const& { return m_storage; }

+    constexpr void*       uninit_ptr() &      { return m_storage; }

 

     // @Safety Pointer must only be accessed when in initialized state.

-    constexpr const T* init_ptr(unsafe) const { return reinterpret_cast<const T*>(m_storage); }

-    constexpr       T* init_ptr(unsafe)       { return reinterpret_cast<      T*>(m_storage); }

+    constexpr       T* init_ptr_unsafe() && = delete;

+    constexpr const T* init_ptr_unsafe() const& { return &m_value; }

+    constexpr       T* init_ptr_unsafe() &      { return &m_value; }

 

     // @Safety Reference must only be accessed when in initialized state.

-    constexpr const T& as_init(unsafe) const { return *reinterpret_cast<const T*>(m_storage); }

-    constexpr       T& as_init(unsafe)       { return *reinterpret_cast<      T*>(m_storage); }

+    constexpr       T& as_init_unsafe() && = delete;

+    constexpr const T& as_init_unsafe() const& { return m_value; }

+    constexpr       T& as_init_unsafe() &      { return m_value; }

 

     // @Safety Must be called only when in uninitialized state.

     template<typename... Args>

-    inline void init(unsafe, Args&&... args)

+    constexpr void init_unsafe(Args&&... args) &

     {

         new(uninit_ptr()) T(ASL_FWD(args)...);

     }

 

     // @Safety Must be called only when in initialized state.

-    inline void uninit(unsafe)

+    constexpr void uninit_unsafe() &

     {

         if constexpr (!trivially_destructible<T>)

         {

-            init_ptr(unsafe("Caller has checked init state"))->~T();

+            init_ptr_unsafe()->~T();

         }

     }

 };