box.h

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/*
Copyright (c) 2026 MrXie1109
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
 
#pragma once
#include <vector>
#include <typeinfo>
#include <utility>
#include <ostream>
#include <memory>
#include <cstdlib>
#include "strpp.h"
#include "csexc.h"
#include "literals.h"
 
namespace console
{
    class Item
    {
    private:
        struct Base
        {
            virtual ~Base() {}
            virtual Base *clone() const = 0;                
            virtual void print(std::ostream &) const = 0;   
            virtual std::string str() const = 0;            
            virtual const std::type_info &type() const = 0; 
        };

        template <typename T>
        struct Derived : Base
        {
            T value; 

            Derived(const T &v) : value(v) {}

            Derived(T &&v) : value(std::move(v)) {}

            Base *clone() const override
            {
                return new Derived(value);
            }

            void print(std::ostream &os) const override
            {
                repr(value, os);
            }

            std::string str() const override
            {
                std::ostringstream oss;
                repr(value, oss);
                return oss.str();
            }

            const std::type_info &type() const override
            {
                return typeid(T);
            }
        };
 
        Base *ptr; 
 
    public:
        Item() : ptr(nullptr) {}

        template <typename T>
        Item(T &&value)
            : ptr(new Derived<typename std::decay<T>::type>(
                  std::forward<T>(value))) {}

        Item(const Item &other)
            : ptr(other.ptr ? other.ptr->clone() : nullptr) {}

        Item(Item &&other) noexcept : ptr(other.ptr)
        {
            other.ptr = nullptr;
        }

        template <typename T>
        T &get()
        {
            if (ptr == nullptr)
                throw bad_get("empty item");
            if (typeid(T) != ptr->type())
                throw bad_get(std::string("type mismatch: ") +
                              tiname(typeid(T)) +
                              " and " +
                              tiname(ptr->type()));
            return ((Derived<T> *)ptr)->value;
        }

        template <typename T>
        T &unsafe_get()
        {
            return ((Derived<T> *)ptr)->value;
        }

        template <typename T>
        const T &get() const
        {
            if (ptr == nullptr)
                throw bad_get("empty item");
            if (typeid(T) != ptr->type())
                throw bad_get(std::string("type mismatch: ") +
                              typeid(T).name() +
                              " and " +
                              ptr->type().name());
            return ((Derived<T> *)ptr)->value;
        }

        template <typename T>
        const T &unsafe_get() const
        {
            return ((Derived<T> *)ptr)->value;
        }

        const Item &operator=(const Item &other)
        {
            if (this != &other)
            {
                Base *new_ptr = other.ptr ? other.ptr->clone() : nullptr;
                delete ptr;
                ptr = new_ptr;
            }
            return *this;
        }

        const Item &operator=(Item &&other) noexcept
        {
            if (this != &other)
            {
                delete ptr;
                ptr = other.ptr;
                other.ptr = nullptr;
            }
            return *this;
        }

        friend std::ostream &operator<<(std::ostream &os, const Item &item)
        {
            item.ptr->print(os);
            return os;
        }

        std::string str() const
        {
            return ptr->str();
        }

        ~Item() { delete ptr; }
    };

    class Box : public std::vector<Item>
    {
    public:
        template <class... Args>
        Box(Args &&...args)
            : std::vector<Item>({Item(std::forward<Args>(args))...}) {}

        template <class T>
        T &get(size_t index)
        {
            return std::vector<Item>::at(index).get<T>();
        }

        template <typename T>
        T &unsafe_get(size_t index)
        {
            return std::vector<Item>::operator[](index).unsafe_get<T>();
        }

        template <class... Args>
        void unpack(Args &...args)
        {
            size_t i = 0;
            int _[] = {0, ((args = get<Args>(i++)), 0)...};
            (void)_;
        }

        template <class... Args>
        void unsafe_unpack(Args &...args)
        {
            size_t i = 0;
            int _[] = {0, ((args = unsafe_get<Args>(i++)), 0)...};
            (void)_;
        }

        friend std::ostream &operator<<(std::ostream &os, const Box &box)
        {
            if (box.empty())
                return os << "()";
            auto it = box.begin();
            os << '(' << *it;
            while (++it != box.end())
                os << ", " << *it;
            return os << ')';
        }
    };
}