зеркало из https://github.com/mozilla/gecko-dev.git
54 строки
1.5 KiB
C++
54 строки
1.5 KiB
C++
/* -*- 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
|