dom/bindings/UnionMember.h

   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:
  25   T& SetValue()
  26   {
  27     new (mStorage.addr()) T();
  28     return *mStorage.addr();
  29   }
  30   template <typename T1>
  31   T& SetValue(const T1& aValue)
  32   {
  33     new (mStorage.addr()) T(aValue);
  34     return *mStorage.addr();
  35   }
  36   template<typename T1, typename T2>
  37   T& SetValue(const T1& aValue1, const T2& aValue2)
  38   {
  39     new (mStorage.addr()) T(aValue1, aValue2);
  40     return *mStorage.addr();
  41   }
  42   T& Value()
  43   {
  44     return *mStorage.addr();
  45   }
  46   const T& Value() const
  47   {
  48     return *mStorage.addr();
  49   }
  50   void Destroy()
  51   {
  52     mStorage.addr()->~T();
  53   }
  54 };
  55
  56 } // namespace dom
  57 } // namespace mozilla
  58
  59 #endif // mozilla_dom_UnionMember_h