/* -*- 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 type suitable for returning either a value or an error from a function. */
#ifndef mozilla_ResultVariant_h
#define mozilla_ResultVariant_h
#include "mozilla/MaybeStorageBase.h"
#include "mozilla/Result.h"
#include "mozilla/Variant.h"
namespace mozilla::detail {
template <
typename V,
typename E>
class ResultImplementation<V, E, PackingStrategy::Variant> {
mozilla::Variant<V, E> mStorage;
public:
static constexpr PackingStrategy Strategy = PackingStrategy::Variant;
ResultImplementation(ResultImplementation&&) =
default;
ResultImplementation(
const ResultImplementation&) =
delete;
ResultImplementation&
operator=(
const ResultImplementation&) =
delete;
ResultImplementation&
operator=(ResultImplementation&&) =
default;
explicit ResultImplementation(V&& aValue) : mStorage(std::move(aValue)) {}
explicit ResultImplementation(
const V& aValue) : mStorage(aValue) {}
template <
typename... Args>
explicit ResultImplementation(std::in_place_t, Args&&... aArgs)
: mStorage(VariantType<V>{}, std::forward<Args>(aArgs)...) {}
explicit ResultImplementation(
const E& aErrorValue) : mStorage(aErrorValue) {}
explicit ResultImplementation(E&& aErrorValue)
: mStorage(std::move(aErrorValue)) {}
bool isOk()
const {
return mStorage.
template is<V>(); }
// The callers of these functions will assert isOk() has the proper value, so
// these functions (in all ResultImplementation specializations) don't need
// to do so.
V unwrap() {
return std::move(mStorage.
template as<V>()); }
const V& inspect()
const {
return mStorage.
template as<V>(); }
E unwrapErr() {
return std::move(mStorage.
template as<E>()); }
const E& inspectErr()
const {
return mStorage.
template as<E>(); }
void updateAfterTracing(V&& aValue) {
mStorage.
template emplace<V>(std::move(aValue));
}
void updateErrorAfterTracing(E&& aErrorValue) {
mStorage.
template emplace<E>(std::move(aErrorValue));
}
};
}
// namespace mozilla::detail
#endif // mozilla_ResultVariant_h
