mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-12-05 03:54:35 +00:00
ae75c3faa8
Also make CompactPair<A, B> a literal type if A and B are literal types, and add MaybeStorageBase that ought to be used as a basis of MaybeStorage in a follow-up patch. Differential Revision: https://phabricator.services.mozilla.com/D55930
54 lines
2.0 KiB
C++
54 lines
2.0 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 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:
|
|
ResultImplementation(ResultImplementation&&) = default;
|
|
ResultImplementation(const ResultImplementation&) = delete;
|
|
ResultImplementation& operator=(const ResultImplementation&) = delete;
|
|
ResultImplementation& operator=(ResultImplementation&&) = default;
|
|
|
|
explicit ResultImplementation(V&& aValue)
|
|
: mStorage(std::forward<V>(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::forward<E>(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>(); }
|
|
};
|
|
|
|
} // namespace mozilla::detail
|
|
|
|
#endif // mozilla_ResultVariant_h
|