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