hardcoresushi/libcryfs
1
0
Fork 0
Code Issues Pull Requests Releases Activity

Remove own either

Browse Source
This commit is contained in:
Sebastian Messmer 2018-12-24 18:35:47 +01:00
parent ebecf44b40
commit 9246856f76
1 changed files with 0 additions and 221 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

221
src/cpp-utils/either.h
View File

@ -1,221 +0,0 @@
#pragma once
#ifndef MESSMER_CPPUTILS_EITHER_H
#define MESSMER_CPPUTILS_EITHER_H
#include <boost/optional.hpp>
#include <iostream>
#include "assert/assert.h"
namespace cpputils {
template<class Left, class Right>
class either final {
public:
//TODO Try allowing construction with any type that std::is_convertible to Left or Right.
either(const Left &left): _side(Side::left) {
_construct_left(left);
}
either(Left &&left): _side(Side::left) {
_construct_left(std::move(left));
}
either(const Right &right): _side(Side::right) {
_construct_right(right);
}
either(Right &&right): _side(Side::right) {
_construct_right(std::move(right));
}
//TODO Try allowing copy-construction when Left/Right types are std::is_convertible
either(const either<Left, Right> &rhs): _side(rhs._side) {
if(_side == Side::left) {
_construct_left(rhs._left);
} else {
_construct_right(rhs._right);
}
}
either(either<Left, Right> &&rhs): _side(rhs._side) {
if(_side == Side::left) {
_construct_left(std::move(rhs._left));
} else {
_construct_right(std::move(rhs._right));
}
}
~either() {
_destruct();
}
//TODO Try allowing copy-assignment when Left/Right types are std::is_convertible
either<Left, Right> &operator=(const either<Left, Right> &rhs) {
_destruct();
_side = rhs._side;
if (_side == Side::left) {
_construct_left(rhs._left);
} else {
_construct_right(rhs._right);
}
return *this;
}
either<Left, Right> &operator=(either<Left, Right> &&rhs) {
_destruct();
_side = rhs._side;
if (_side == Side::left) {
_construct_left(std::move(rhs._left));
} else {
_construct_right(std::move(rhs._right));
}
return *this;
}
//TODO fold, map_left, map_right, left_or_else(val), right_or_else(val), left_or_else(func), right_or_else(func)
bool is_left() const {
return _side == Side::left;
}
bool is_right() const {
return _side == Side::right;
}
const Left &left() const& {
ASSERT(is_left(), "Tried to get left side of an either which is right.");
return _left; // NOLINT(cppcoreguidelines-pro-type-union-access)
}
Left &left() & {
return const_cast<Left&>(const_cast<const either<Left, Right>*>(this)->left());
}
Left &&left() && {
return std::move(left());
}
const Right &right() const& {
ASSERT(is_right(), "Tried to get right side of an either which is left.");
return _right; // NOLINT(cppcoreguidelines-pro-type-union-access)
}
Right &right() & {
return const_cast<Right&>(const_cast<const either<Left, Right>*>(this)->right());
}
Right &&right() && {
return std::move(right());
}
boost::optional<const Left&> left_opt() const& {
if (_side == Side::left) {
return _left; // NOLINT(cppcoreguidelines-pro-type-union-access)
} else {
return boost::none;
}
}
boost::optional<Left&> left_opt() & {
if (_side == Side::left) {
return _left; // NOLINT(cppcoreguidelines-pro-type-union-access)
} else {
return boost::none;
}
}
boost::optional<Left> left_opt() && {
if (_side == Side::left) {
return std::move(_left); // NOLINT(cppcoreguidelines-pro-type-union-access)
} else {
return boost::none;
}
}
boost::optional<const Right&> right_opt() const& {
if (_side == Side::right) {
return _right; // NOLINT(cppcoreguidelines-pro-type-union-access)
} else {
return boost::none;
}
}
boost::optional<Right&> right_opt() & {
if (_side == Side::right) {
return _right; // NOLINT(cppcoreguidelines-pro-type-union-access)
} else {
return boost::none;
}
}
boost::optional<Right> right_opt() && {
if (_side == Side::right) {
return std::move(_right); // NOLINT(cppcoreguidelines-pro-type-union-access)
} else {
return boost::none;
}
}
private:
union {
Left _left;
Right _right;
};
enum class Side : unsigned char {left, right} _side;
either(Side side): _side(side) {}
template<typename... Args>
void _construct_left(Args&&... args) {
new(&_left)Left(std::forward<Args>(args)...); // NOLINT(cppcoreguidelines-pro-type-union-access)
}
template<typename... Args>
void _construct_right(Args&&... args) {
new(&_right)Right(std::forward<Args>(args)...); // NOLINT(cppcoreguidelines-pro-type-union-access)
}
void _destruct() {
if (_side == Side::left) {
_left.~Left(); // NOLINT(cppcoreguidelines-pro-type-union-access)
} else {
_right.~Right(); // NOLINT(cppcoreguidelines-pro-type-union-access)
}
}
template<typename Left_, typename Right_, typename... Args>
friend either<Left_, Right_> make_left(Args&&... args);
template<typename Left_, typename Right_, typename... Args>
friend either<Left_, Right_> make_right(Args&&... args);
};
template<class Left, class Right>
bool operator==(const either<Left, Right> &lhs, const either<Left, Right> &rhs) {
if (lhs.is_left() != rhs.is_left()) {
return false;
}
if (lhs.is_left()) {
return lhs.left() == rhs.left();
} else {
return lhs.right() == rhs.right();
}
}
template<class Left, class Right>
bool operator!=(const either<Left, Right> &lhs, const either<Left, Right> &rhs) {
return !operator==(lhs, rhs);
}
template<class Left, class Right>
std::ostream &operator<<(std::ostream &stream, const either<Left, Right> &value) {
if (value.is_left()) {
stream << "Left(" << value.left() << ")";
} else {
stream << "Right(" << value.right() << ")";
}
return stream;
}
template<typename Left, typename Right, typename... Args>
either<Left, Right> make_left(Args&&... args) {
either<Left, Right> result(either<Left, Right>::Side::left);
result._construct_left(std::forward<Args>(args)...);
return result;
}
template<typename Left, typename Right, typename... Args>
either<Left, Right> make_right(Args&&... args) {
either<Left, Right> result(either<Left, Right>::Side::right);
result._construct_right(std::forward<Args>(args)...);
return result;
}
}
#endif