Result: Use Option as backend

luna/include/luna/Result.h

@@ -1,6 +1,7 @@
 #pragma once
 #include <luna/Check.h>
 #include <luna/Move.h>
+#include <luna/Option.h>
 #include <luna/PlacementNew.h>
 #include <luna/SystemError.h>
 #include <luna/Types.h>
@@ -18,25 +19,22 @@ struct Error
 template <typename T> class Result
 {
   public:
-    Result(const T& value)
+    Result(const T& value) : m_value(value)
     {
-        m_storage.store_reference(value);
         m_has_value = true;
         m_has_error = false;
     }
 
-    Result(T&& value)
+    Result(T&& value) : m_value(value)
     {
-        m_storage.store_movable_reference(move(value));
         m_has_value = true;
         m_has_error = false;
     }
 
-    Result(const Result<T>& other)
+    Result(const Result<T>& other) : m_value(other.m_value)
     {
         if (!other.m_has_error)
         {
-            m_storage.store_reference(other.m_storage.fetch_reference());
             m_has_value = true;
             m_has_error = false;
         }
@@ -48,11 +46,10 @@ template <typename T> class Result
         }
     }
 
-    Result(Result<T>&& other)
+    Result(Result<T>&& other) : m_value(other.m_value)
     {
         if (!other.m_has_error)
         {
-            m_storage.store_movable_reference(move(other.m_storage.fetch_reference()));
             m_has_value = true;
             m_has_error = false;
         }
@@ -64,7 +61,7 @@ template <typename T> class Result
         }
     }
 
-    Result(const Error& err)
+    Result(const Error& err) : m_value()
     {
         m_error = err.error;
         m_has_error = true;
@@ -102,98 +99,39 @@ template <typename T> class Result
     T value()
     {
         expect(has_value(), "Result::value() called on a Result that holds an error");
-        return m_storage.fetch_reference();
+        return m_value.value();
     }
 
     T expect_value(const char* reason)
     {
         expect(has_value(), reason);
-        return m_storage.fetch_reference();
+        return move(m_value.release_value());
     }
 
-    T value_or(T other)
+    T value_or(const T& other)
     {
-        if (has_value()) return m_storage.fetch_reference();
+        return m_value.value_or(other);
-        return other;
     }
 
     bool try_set_value(T& ref)
     {
-        if (!has_value()) return false;
+        return m_value.try_set_value(ref);
-        ref = m_storage.fetch_reference();
-        return true;
     }
 
     T release_value()
     {
         expect(has_value(), "Result::release_value() called on a Result that holds an error");
-        T item = m_storage.fetch_reference();
+        return m_value.release_value();
-        m_has_value = false;
-        m_storage.destroy();
-        return move(item);
     }
 
     T expect_release_value(const char* reason)
     {
         expect(has_value(), reason);
-        T item = m_storage.fetch_reference();
+        return m_value.release_value();
-        m_has_value = false;
-        m_storage.destroy();
-        return move(item);
-    }
-
-    ~Result()
-    {
-        if (has_value()) m_storage.destroy();
     }
 
   private:
-    struct Storage
+    Option<T> m_value;
-    {
-        u8 buffer[sizeof(T)];
-
-        T* fetch_ptr()
-        {
-            return (T*)buffer;
-        }
-
-        T& fetch_reference()
-        {
-            return *fetch_ptr();
-        }
-
-        const T* fetch_ptr() const
-        {
-            return (const T*)buffer;
-        }
-
-        const T& fetch_reference() const
-        {
-            return *fetch_ptr();
-        }
-
-        void store_ptr(T* ptr)
-        {
-            new (buffer) T(*ptr);
-        }
-
-        void store_reference(const T& ref)
-        {
-            new (buffer) T(ref);
-        }
-
-        void store_movable_reference(T&& ref)
-        {
-            new (buffer) T(ref);
-        }
-
-        void destroy()
-        {
-            fetch_reference().~T();
-        }
-    };
-
-    Storage m_storage;
     int m_error;
     bool m_has_error;
     bool m_has_value;
@@ -289,6 +227,6 @@ template <> class Result<void>
 #define TRY(expr)                                                                                                      \
     ({                                                                                                                 \
         auto _expr_rc = (expr);                                                                                        \
-        if (_expr_rc.has_error()) return _expr_rc.release_error();                                                     \
+        if (!_expr_rc.has_value()) return _expr_rc.release_error();                                                    \
         _expr_rc.expect_release_value("sanity check failed: has_error() returned false, yet result has no value");     \
     })