libcryfs/src/cpp-utils/either.h

#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:
        template<class Head, class... Tail, std::enable_if_t<std::is_constructible<Left, Head, Tail...>::value && !std::is_constructible<Right, Head, Tail...>::value>* = nullptr>
        either(Head&& construct_left_head_arg, Tail&&... construct_left_tail_args) noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(std::forward<Head>(construct_left_head_arg), std::forward<Tail>(construct_left_tail_args)...)))
                : _side(Side::left) {
            _construct_left(std::forward<Head>(construct_left_head_arg), std::forward<Tail>(construct_left_tail_args)...);
        }

        template<class Head, class... Tail, std::enable_if_t<!std::is_constructible<Left, Head, Tail...>::value && std::is_constructible<Right, Head, Tail...>::value>* = nullptr>
        either(Head&& construct_right_head_arg, Tail&&... construct_right_tail_args) noexcept(noexcept(std::declval<either<Left, Right>>()._construct_right(std::forward<Head>(construct_right_head_arg), std::forward<Tail>(construct_right_tail_args)...)))
            : _side(Side::right) {
          _construct_right(std::forward<Head>(construct_right_head_arg), std::forward<Tail>(construct_right_tail_args)...);
        }

        //TODO Try allowing copy-construction when Left/Right types are std::is_convertible
        either(const either<Left, Right> &rhs) noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(rhs._left)) && noexcept(std::declval<either<Left, Right>>()._construct_right(rhs._right)))
                : _side(rhs._side) {
            if(_side == Side::left) {
                _construct_left(rhs._left);  // NOLINT(cppcoreguidelines-pro-type-union-access)
            } else {
                _construct_right(rhs._right);  // NOLINT(cppcoreguidelines-pro-type-union-access)
            }
        }

        either(either<Left, Right> &&rhs) noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(std::move(rhs._left))) && noexcept(std::declval<either<Left, Right>>()._construct_right(std::move(rhs._right))))
                : _side(rhs._side) {
            if(_side == Side::left) {
                _construct_left(std::move(rhs._left));  // NOLINT(cppcoreguidelines-pro-type-union-access)
            } else {
                _construct_right(std::move(rhs._right));  // NOLINT(cppcoreguidelines-pro-type-union-access)
            }
        }

        ~either() {
            _destruct();
        }

        //TODO Try allowing copy-assignment when Left/Right types are std::is_convertible
        // NOLINTNEXTLINE(cert-oop54-cpp)
        either<Left, Right> &operator=(const either<Left, Right> &rhs) noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(rhs._left)) && noexcept(std::declval<either<Left, Right>>()._construct_right(rhs._right))) {
            if (this == &rhs) {
                return *this;
            }

            _destruct();
            _side = rhs._side;
            if (_side == Side::left) {
                _construct_left(rhs._left);  // NOLINT(cppcoreguidelines-pro-type-union-access)
            } else {
                _construct_right(rhs._right);  // NOLINT(cppcoreguidelines-pro-type-union-access)
            }
            return *this;
        }

        either<Left, Right> &operator=(either<Left, Right> &&rhs) noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(std::move(rhs._left))) && noexcept(std::declval<either<Left, Right>>()._construct_right(std::move(rhs._right)))) {
            if (this == &rhs) {
                return *this;
            }

            _destruct();
            _side = rhs._side;
            if (_side == Side::left) {
                _construct_left(std::move(rhs._left));  // NOLINT(cppcoreguidelines-pro-type-union-access)
            } else {
                _construct_right(std::move(rhs._right));  // NOLINT(cppcoreguidelines-pro-type-union-access)
            }
            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 noexcept {
            return _side == Side::left;
        }

        bool is_right() const noexcept {
            return _side == Side::right;
        }

        const Left &left() const& {
            if (!is_left()) {
              throw std::logic_error("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& {
            if (!is_right()) {
              throw std::logic_error("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& noexcept {
            if (_side == Side::left) {
                return _left;  // NOLINT(cppcoreguidelines-pro-type-union-access)
            } else {
                return boost::none;
            }
        }
        boost::optional<Left&> left_opt() & noexcept {
            if (_side == Side::left) {
                return _left;  // NOLINT(cppcoreguidelines-pro-type-union-access)
            } else {
                return boost::none;
            }
        }
        // warning: opposed to the other left_opt variants, this one already moves the content and returns by value.
        boost::optional<Left> left_opt() && noexcept(noexcept(boost::optional<Left>(std::move(std::declval<either<Left, Right>>()._left)))) {
            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& noexcept {
            if (_side == Side::right) {
                return _right;  // NOLINT(cppcoreguidelines-pro-type-union-access)
            } else {
                return boost::none;
            }
        }
        boost::optional<Right&> right_opt() & noexcept {
            if (_side == Side::right) {
                return _right;  // NOLINT(cppcoreguidelines-pro-type-union-access)
            } else {
                return boost::none;
            }
        }
        // warning: opposed to the other left_opt variants, this one already moves the content and returns by value.
        boost::optional<Right> right_opt() && noexcept(noexcept(boost::optional<Right>(std::move(std::declval<either<Left, Right>>()._right)))) {
            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 : uint8_t {left, right} _side;

        explicit either(Side side) noexcept : _side(side) {}

        template<typename... Args>
        void _construct_left(Args&&... args) noexcept(noexcept(new Left(std::forward<Args>(args)...))) {
            new(&_left)Left(std::forward<Args>(args)...);  // NOLINT(cppcoreguidelines-pro-type-union-access)
        }
        template<typename... Args>
        void _construct_right(Args&&... args) noexcept(noexcept(new Right(std::forward<Args>(args)...))) {
            new(&_right)Right(std::forward<Args>(args)...);  // NOLINT(cppcoreguidelines-pro-type-union-access)
        }
        void _destruct() noexcept {
            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) /* TODO noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(std::forward<Args>(args)...))) */;

        template<typename Left_, typename Right_, typename... Args>
        friend either<Left_, Right_> make_right(Args&&... args) /* TODO noexcept(noexcept(std::declval<either<Left, Right>>()._construct_right(std::forward<Args>(args)...))) */;
    };

    template<class Left, class Right>
    inline bool operator==(const either<Left, Right> &lhs, const either<Left, Right> &rhs) noexcept(noexcept(std::declval<Left>() == std::declval<Left>()) && noexcept(std::declval<Right>() == std::declval<Right>())) {
        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>
    inline bool operator!=(const either<Left, Right> &lhs, const either<Left, Right> &rhs) noexcept(noexcept(operator==(lhs, rhs))) {
        return !operator==(lhs, rhs);
    }

    template<class Left, class Right>
    inline 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>
    inline either<Left, Right> make_left(Args&&... args) /* TODO noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(std::forward<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>
    inline either<Left, Right> make_right(Args&&... args) /* TODO noexcept(noexcept(std::declval<either<Left, Right>>()._construct_right(std::forward<Args>(args)...))) */ {
        either<Left, Right> result(either<Left, Right>::Side::right);
        result._construct_right(std::forward<Args>(args)...);
        return result;
    }
}


#endif
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`#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:`
Fix and add test cases 2018-12-24 18:15:08 +01:00			`template<class Head, class... Tail, std::enable_if_t<std::is_constructible<Left, Head, Tail...>::value && !std::is_constructible<Right, Head, Tail...>::value>* = nullptr>`
More noexcept specifiers 2018-12-24 18:34:42 +01:00			`either(Head&& construct_left_head_arg, Tail&&... construct_left_tail_args) noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(std::forward<Head>(construct_left_head_arg), std::forward<Tail>(construct_left_tail_args)...)))`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`: _side(Side::left) {`
Fix and add test cases 2018-12-24 18:15:08 +01:00			`_construct_left(std::forward<Head>(construct_left_head_arg), std::forward<Tail>(construct_left_tail_args)...);`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`}`

Fix and add test cases 2018-12-24 18:15:08 +01:00			`template<class Head, class... Tail, std::enable_if_t<!std::is_constructible<Left, Head, Tail...>::value && std::is_constructible<Right, Head, Tail...>::value>* = nullptr>`
More noexcept specifiers 2018-12-24 18:34:42 +01:00			`either(Head&& construct_right_head_arg, Tail&&... construct_right_tail_args) noexcept(noexcept(std::declval<either<Left, Right>>()._construct_right(std::forward<Head>(construct_right_head_arg), std::forward<Tail>(construct_right_tail_args)...)))`
Fix and add test cases 2018-12-24 18:15:08 +01:00			`: _side(Side::right) {`
			`_construct_right(std::forward<Head>(construct_right_head_arg), std::forward<Tail>(construct_right_tail_args)...);`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`}`

			`//TODO Try allowing copy-construction when Left/Right types are std::is_convertible`
			`either(const either<Left, Right> &rhs) noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(rhs._left)) && noexcept(std::declval<either<Left, Right>>()._construct_right(rhs._right)))`
			`: _side(rhs._side) {`
			`if(_side == Side::left) {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`_construct_left(rhs._left); // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`} else {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`_construct_right(rhs._right); // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`}`
			`}`

fix 2018-12-28 09:47:22 +01:00			`either(either<Left, Right> &&rhs) noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(std::move(rhs._left))) && noexcept(std::declval<either<Left, Right>>()._construct_right(std::move(rhs._right))))`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`: _side(rhs._side) {`
			`if(_side == Side::left) {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`_construct_left(std::move(rhs._left)); // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`} else {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`_construct_right(std::move(rhs._right)); // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`}`
			`}`

			`~either() {`
			`_destruct();`
			`}`

			`//TODO Try allowing copy-assignment when Left/Right types are std::is_convertible`
Update CI to clang-tidy 9 and fix warnings 2020-07-22 10:32:43 -07:00			`// NOLINTNEXTLINE(cert-oop54-cpp)`
fix 2018-12-28 09:47:22 +01:00			`either<Left, Right> &operator=(const either<Left, Right> &rhs) noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(rhs._left)) && noexcept(std::declval<either<Left, Right>>()._construct_right(rhs._right))) {`
Update CI to clang-tidy 9 and fix warnings 2020-07-22 10:32:43 -07:00			`if (this == &rhs) {`
			`return *this;`
			`}`

[wip] Implement either type 2018-10-27 21:20:40 -07:00			`_destruct();`
			`_side = rhs._side;`
			`if (_side == Side::left) {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`_construct_left(rhs._left); // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`} else {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`_construct_right(rhs._right); // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`}`
			`return *this;`
			`}`

fix 2018-12-28 09:47:22 +01:00			`either<Left, Right> &operator=(either<Left, Right> &&rhs) noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(std::move(rhs._left))) && noexcept(std::declval<either<Left, Right>>()._construct_right(std::move(rhs._right)))) {`
Update CI to clang-tidy 9 and fix warnings 2020-07-22 10:32:43 -07:00			`if (this == &rhs) {`
			`return *this;`
			`}`

[wip] Implement either type 2018-10-27 21:20:40 -07:00			`_destruct();`
			`_side = rhs._side;`
			`if (_side == Side::left) {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`_construct_left(std::move(rhs._left)); // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`} else {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`_construct_right(std::move(rhs._right)); // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`}`
			`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 noexcept {`
			`return _side == Side::left;`
			`}`

			`bool is_right() const noexcept {`
			`return _side == Side::right;`
			`}`

			`const Left &left() const& {`
fix debug builds 2018-12-25 10:34:40 +01:00			`if (!is_left()) {`
			`throw std::logic_error("Tried to get left side of an either which is right.");`
			`}`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`return _left; // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`}`
			`Left &left() & {`
			`return const_cast<Left&>(const_cast<const either<Left, Right>*>(this)->left());`
			`}`
			`Left &&left() && {`
			`return std::move(left());`
			`}`

			`const Right &right() const& {`
fix debug builds 2018-12-25 10:34:40 +01:00			`if (!is_right()) {`
			`throw std::logic_error("Tried to get right side of an either which is left.");`
			`}`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`return _right; // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`}`
			`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& noexcept {`
			`if (_side == Side::left) {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`return _left; // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`} else {`
			`return boost::none;`
			`}`
			`}`
			`boost::optional<Left&> left_opt() & noexcept {`
			`if (_side == Side::left) {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`return _left; // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`} else {`
			`return boost::none;`
			`}`
			`}`
Re-enable light_opt()&& and left_opt()&& 2018-12-25 10:40:46 +01:00			`// warning: opposed to the other left_opt variants, this one already moves the content and returns by value.`
fix 2018-12-29 11:58:38 +01:00			`boost::optional<Left> left_opt() && noexcept(noexcept(boost::optional<Left>(std::move(std::declval<either<Left, Right>>()._left)))) {`
Re-enable light_opt()&& and left_opt()&& 2018-12-25 10:40:46 +01:00			`if (_side == Side::left) {`
fix 2018-12-29 22:38:54 +01:00			`return std::move(_left); // NOLINT(cppcoreguidelines-pro-type-union-access)`
Re-enable light_opt()&& and left_opt()&& 2018-12-25 10:40:46 +01:00			`} else {`
			`return boost::none;`
			`}`
			`}`

[wip] Implement either type 2018-10-27 21:20:40 -07:00
			`boost::optional<const Right&> right_opt() const& noexcept {`
			`if (_side == Side::right) {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`return _right; // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`} else {`
			`return boost::none;`
			`}`
			`}`
			`boost::optional<Right&> right_opt() & noexcept {`
			`if (_side == Side::right) {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`return _right; // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`} else {`
			`return boost::none;`
			`}`
			`}`
Re-enable light_opt()&& and left_opt()&& 2018-12-25 10:40:46 +01:00			`// warning: opposed to the other left_opt variants, this one already moves the content and returns by value.`
fix 2018-12-29 11:58:38 +01:00			`boost::optional<Right> right_opt() && noexcept(noexcept(boost::optional<Right>(std::move(std::declval<either<Left, Right>>()._right)))) {`
Re-enable light_opt()&& and left_opt()&& 2018-12-25 10:40:46 +01:00			`if (_side == Side::right) {`
fix 2018-12-29 22:38:54 +01:00			`return std::move(_right); // NOLINT(cppcoreguidelines-pro-type-union-access)`
Re-enable light_opt()&& and left_opt()&& 2018-12-25 10:40:46 +01:00			`} else {`
			`return boost::none;`
			`}`
			`}`


[wip] Implement either type 2018-10-27 21:20:40 -07:00
			`private:`
			`union {`
			`Left _left;`
			`Right _right;`
			`};`
			`enum class Side : uint8_t {left, right} _side;`

			`explicit either(Side side) noexcept : _side(side) {}`

			`template<typename... Args>`
			`void _construct_left(Args&&... args) noexcept(noexcept(new Left(std::forward<Args>(args)...))) {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`new(&_left)Left(std::forward<Args>(args)...); // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`}`
			`template<typename... Args>`
			`void _construct_right(Args&&... args) noexcept(noexcept(new Right(std::forward<Args>(args)...))) {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`new(&_right)Right(std::forward<Args>(args)...); // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`}`
			`void _destruct() noexcept {`
			`if (_side == Side::left) {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`_left.~Left(); // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`} else {`
fix clang-tidy 2018-12-25 19:50:53 +01:00			`_right.~Right(); // NOLINT(cppcoreguidelines-pro-type-union-access)`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`}`
			`}`

			`template<typename Left_, typename Right_, typename... Args>`
More noexcept specifiers 2018-12-24 18:34:42 +01:00			`friend either<Left_, Right_> make_left(Args&&... args) /* TODO noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(std::forward<Args>(args)...))) */;`
[wip] Implement either type 2018-10-27 21:20:40 -07:00
			`template<typename Left_, typename Right_, typename... Args>`
More noexcept specifiers 2018-12-24 18:34:42 +01:00			`friend either<Left_, Right_> make_right(Args&&... args) /* TODO noexcept(noexcept(std::declval<either<Left, Right>>()._construct_right(std::forward<Args>(args)...))) */;`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`};`

			`template<class Left, class Right>`
Fix and add test cases 2018-12-24 18:15:08 +01:00			`inline bool operator==(const either<Left, Right> &lhs, const either<Left, Right> &rhs) noexcept(noexcept(std::declval<Left>() == std::declval<Left>()) && noexcept(std::declval<Right>() == std::declval<Right>())) {`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`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>`
Fix and add test cases 2018-12-24 18:15:08 +01:00			`inline bool operator!=(const either<Left, Right> &lhs, const either<Left, Right> &rhs) noexcept(noexcept(operator==(lhs, rhs))) {`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`return !operator==(lhs, rhs);`
			`}`

			`template<class Left, class Right>`
Fix and add test cases 2018-12-24 18:15:08 +01:00			`inline std::ostream &operator<<(std::ostream &stream, const either<Left, Right> &value) {`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`if (value.is_left()) {`
			`stream << "Left(" << value.left() << ")";`
			`} else {`
			`stream << "Right(" << value.right() << ")";`
			`}`
			`return stream;`
			`}`

			`template<typename Left, typename Right, typename... Args>`
Fix and add test cases 2018-12-24 18:15:08 +01:00			`inline either<Left, Right> make_left(Args&&... args) /* TODO noexcept(noexcept(std::declval<either<Left, Right>>()._construct_left(std::forward<Args>(args)...))) */ {`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`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>`
Fix and add test cases 2018-12-24 18:15:08 +01:00			`inline either<Left, Right> make_right(Args&&... args) /* TODO noexcept(noexcept(std::declval<either<Left, Right>>()._construct_right(std::forward<Args>(args)...))) */ {`
[wip] Implement either type 2018-10-27 21:20:40 -07:00			`either<Left, Right> result(either<Left, Right>::Side::right);`
			`result._construct_right(std::forward<Args>(args)...);`
			`return result;`
			`}`
			`}`


			`#endif`