michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set ts=8 sts=2 et sw=2 tw=80: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /* A class for holding the members of a union. */
michael@0: 
michael@0: #ifndef mozilla_dom_UnionMember_h
michael@0: #define mozilla_dom_UnionMember_h
michael@0: 
michael@0: #include "mozilla/Alignment.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace dom {
michael@0: 
michael@0: // The union type has an enum to keep track of which of its UnionMembers has
michael@0: // been constructed.
michael@0: template<class T>
michael@0: class UnionMember
michael@0: {
michael@0:   AlignedStorage2<T> mStorage;
michael@0: 
michael@0: public:
michael@0:   T& SetValue()
michael@0:   {
michael@0:     new (mStorage.addr()) T();
michael@0:     return *mStorage.addr();
michael@0:   }
michael@0:   template <typename T1>
michael@0:   T& SetValue(const T1& aValue)
michael@0:   {
michael@0:     new (mStorage.addr()) T(aValue);
michael@0:     return *mStorage.addr();
michael@0:   }
michael@0:   template<typename T1, typename T2>
michael@0:   T& SetValue(const T1& aValue1, const T2& aValue2)
michael@0:   {
michael@0:     new (mStorage.addr()) T(aValue1, aValue2);
michael@0:     return *mStorage.addr();
michael@0:   }
michael@0:   T& Value()
michael@0:   {
michael@0:     return *mStorage.addr();
michael@0:   }
michael@0:   const T& Value() const
michael@0:   {
michael@0:     return *mStorage.addr();
michael@0:   }
michael@0:   void Destroy()
michael@0:   {
michael@0:     mStorage.addr()->~T();
michael@0:   }
michael@0: };
michael@0: 
michael@0: } // namespace dom
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif // mozilla_dom_UnionMember_h