97 lines
2.8 KiB
C++
97 lines
2.8 KiB
C++
/*
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* Copyright (C) 2017 Apple Inc. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
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* THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#pragma once
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#include <wtf/Expected.h>
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namespace WebCore {
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enum class CallbackResultType {
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Success,
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ExceptionThrown,
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UnableToExecute
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};
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template<typename ReturnType> class CallbackResult {
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public:
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CallbackResult(CallbackResultType);
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CallbackResult(ReturnType&&);
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CallbackResultType type() const;
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ReturnType&& releaseReturnValue();
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private:
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Expected<ReturnType, CallbackResultType> m_value;
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};
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template<> class CallbackResult<void> {
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public:
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CallbackResult() = default;
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CallbackResult(CallbackResultType);
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CallbackResultType type() const;
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private:
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CallbackResultType m_type = CallbackResultType::Success;
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};
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template<typename ReturnType> inline CallbackResult<ReturnType>::CallbackResult(CallbackResultType type)
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: m_value(makeUnexpected(type))
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{
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}
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template<typename ReturnType> inline CallbackResult<ReturnType>::CallbackResult(ReturnType&& returnValue)
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: m_value(WTFMove(returnValue))
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{
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}
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template<typename ReturnType> inline CallbackResultType CallbackResult<ReturnType>::type() const
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{
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return m_value.has_value() ? CallbackResultType::Success : m_value.error();
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}
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template<typename ReturnType> inline auto CallbackResult<ReturnType>::releaseReturnValue() -> ReturnType&&
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{
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ASSERT(m_value.has_value());
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return WTFMove(m_value.value());
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}
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// Void specialization
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inline CallbackResult<void>::CallbackResult(CallbackResultType type)
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: m_type(type)
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{
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}
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inline CallbackResultType CallbackResult<void>::type() const
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{
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return m_type;
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}
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}
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