1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4  * License, v. 2.0. If a copy of the MPL was not distributed with this
5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 
7 /* A class for holding the members of a union. */
8 
9 #ifndef mozilla_dom_UnionMember_h
10 #define mozilla_dom_UnionMember_h
11 
12 #include "mozilla/Alignment.h"
13 
14 namespace mozilla {
15 namespace dom {
16 
17 // The union type has an enum to keep track of which of its UnionMembers has
18 // been constructed.
19 template<class T>
20 class UnionMember
21 {
22   AlignedStorage2<T> mStorage;
23 
24 public:
SetValue()25   T& SetValue()
26   {
27     new (mStorage.addr()) T();
28     return *mStorage.addr();
29   }
30   template <typename T1>
SetValue(const T1 & aValue)31   T& SetValue(const T1& aValue)
32   {
33     new (mStorage.addr()) T(aValue);
34     return *mStorage.addr();
35   }
36   template<typename T1, typename T2>
SetValue(const T1 & aValue1,const T2 & aValue2)37   T& SetValue(const T1& aValue1, const T2& aValue2)
38   {
39     new (mStorage.addr()) T(aValue1, aValue2);
40     return *mStorage.addr();
41   }
Value()42   T& Value()
43   {
44     return *mStorage.addr();
45   }
Value()46   const T& Value() const
47   {
48     return *mStorage.addr();
49   }
Destroy()50   void Destroy()
51   {
52     mStorage.addr()->~T();
53   }
54 };
55 
56 } // namespace dom
57 } // namespace mozilla
58 
59 #endif // mozilla_dom_UnionMember_h
60