mayhem-firmware/firmware/common/optional.hpp
Kyle Reed 98f3bf151f
Lazy line caching for Notepad (#1042)
* easier 'now', start adding text editor

* Adding scrolling to notepad

* Better scrolling

* Better scrolling, off-by-1 bugs

* MVP fit and finish

* Add tiny font and use in Notepad

* Font tweaking, tiny font cursor

* Fix warning

* Format changed files

* WIP No file limit

* WIP - adding CircularBuffer type

* WIP Caching

* add  unit test for circular_buffer

* WIP still have a bug when moving cache forward

* Finish lazy line caching

---------

Co-authored-by: kallanreed <kallanreed@outlook.com>
2023-05-22 13:08:59 -07:00

59 lines
1.7 KiB
C++

/*
* Copyright (C) 2016 Jared Boone, ShareBrained Technology, Inc.
*
* This file is part of PortaPack.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef __OPTIONAL_H__
#define __OPTIONAL_H__
#include <utility>
template <typename T>
class Optional {
public:
constexpr Optional()
: value_{}, valid_{false} {}
constexpr Optional(const T& value)
: value_{value}, valid_{true} {}
constexpr Optional(T&& value)
: value_{std::move(value)}, valid_{true} {}
bool is_valid() const { return valid_; }
// TODO: Throw if not valid?
T& value() & { return value_; }
T& operator*() & { return value_; }
const T& value() const& { return value_; }
const T& operator*() const& { return value_; }
T&& value() && { return value_; }
T&& operator*() && { return value_; }
const T&& value() const&& { return value_; }
const T&& operator*() const&& { return value_; }
T* operator->() { return &value_; }
const T* operator->() const { return &value_; }
private:
T value_;
bool valid_;
};
#endif /*__OPTIONAL_H__*/