blob: 71593acd0e553d737e6fd9a623bf1874c35298ee [file] [log] [blame]
// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef {{"_".join(config.protocol.namespace)}}_Maybe_h
#define {{"_".join(config.protocol.namespace)}}_Maybe_h
//#include "Forward.h"
{% for namespace in config.protocol.namespace %}
namespace {{namespace}} {
{% endfor %}
template<typename T>
class Maybe {
public:
Maybe() : m_value() { }
Maybe(std::unique_ptr<T> value) : m_value(std::move(value)) { }
Maybe(Maybe&& other) : m_value(std::move(other.m_value)) { }
void operator=(std::unique_ptr<T> value) { m_value = std::move(value); }
T* fromJust() const { DCHECK(m_value); return m_value.get(); }
T* fromMaybe(T* defaultValue) const { return m_value ? m_value.get() : defaultValue; }
bool isJust() const { return !!m_value; }
std::unique_ptr<T> takeJust() { DCHECK(m_value); return std::move(m_value); }
private:
std::unique_ptr<T> m_value;
};
template<typename T>
class MaybeBase {
public:
MaybeBase() : m_isJust(false) { }
MaybeBase(T value) : m_isJust(true), m_value(value) { }
MaybeBase(MaybeBase&& other) : m_isJust(other.m_isJust), m_value(std::move(other.m_value)) { }
void operator=(T value) { m_value = value; m_isJust = true; }
T fromJust() const { DCHECK(m_isJust); return m_value; }
T fromMaybe(const T& defaultValue) const { return m_isJust ? m_value : defaultValue; }
bool isJust() const { return m_isJust; }
T takeJust() { DCHECK(m_isJust); return m_value; }
protected:
bool m_isJust;
T m_value;
};
template<>
class Maybe<bool> : public MaybeBase<bool> {
public:
Maybe() { }
Maybe(bool value) : MaybeBase(value) { }
Maybe(Maybe&& other) : MaybeBase(std::move(other)) { }
using MaybeBase::operator=;
};
template<>
class Maybe<int> : public MaybeBase<int> {
public:
Maybe() { }
Maybe(int value) : MaybeBase(value) { }
Maybe(Maybe&& other) : MaybeBase(std::move(other)) { }
using MaybeBase::operator=;
};
template<>
class Maybe<double> : public MaybeBase<double> {
public:
Maybe() { }
Maybe(double value) : MaybeBase(value) { }
Maybe(Maybe&& other) : MaybeBase(std::move(other)) { }
using MaybeBase::operator=;
};
template<>
class Maybe<String> : public MaybeBase<String> {
public:
Maybe() { }
Maybe(const String& value) : MaybeBase(value) { }
Maybe(Maybe&& other) : MaybeBase(std::move(other)) { }
using MaybeBase::operator=;
};
{% for namespace in config.protocol.namespace %}
} // namespace {{namespace}}
{% endfor %}
#endif // !defined({{"_".join(config.protocol.namespace)}}_Maybe_h)