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An operation often has two pieces of underlying information: * the data returned as a result from that operation * an error that occurred while retrieving that data Merely returning the data is not good enough. Result<> allows exposing both the data, and the underlying error, and forces (via clang's consumable attribute) you to check for the error before you try to access the data.
78 lines
1.3 KiB
C++
78 lines
1.3 KiB
C++
#pragma once
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#include <AK/Assertions.h>
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#include <AK/Platform.h>
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#include <AK/Optional.h>
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namespace AK {
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template<typename T, typename E>
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class CONSUMABLE(unknown) Result {
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public:
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RETURN_TYPESTATE(unknown)
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Result(const T& res)
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: m_result(res)
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{}
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RETURN_TYPESTATE(unknown)
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Result(const E& error)
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: m_error(error)
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{
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}
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RETURN_TYPESTATE(unknown)
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Result(const T& res, const E& error)
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: m_result(res)
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, m_error(error)
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{
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}
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RETURN_TYPESTATE(unknown)
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Result(Result&& other)
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: m_result(move(other.m_result))
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, m_error(move(other.m_error))
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{
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}
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RETURN_TYPESTATE(unknown)
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Result(Result& other)
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: m_result(other.m_result)
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, m_error(other.m_error)
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{
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}
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CALLABLE_WHEN("unknown", "consumed")
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~Result()
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{}
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CALLABLE_WHEN(consumed)
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T& unwrap() {
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return m_result.value();
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}
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CALLABLE_WHEN(consumed)
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E& error() {
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return m_error.value();
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}
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bool has_error() const {
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return m_error.has_value();
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}
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bool has_value() const {
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return m_result.has_value();
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}
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SET_TYPESTATE(consumed)
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bool failed() const {
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return m_error.value().failed();
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}
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private:
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Optional<T> m_result;
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Optional<E> m_error;
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};
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}
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using AK::Result;
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