Practice. Task 18

// box.hpp
#ifndef _BOX_H_
#define _BOX_H_

class box
{
private:
    unsigned int width;
    unsigned int length;
    unsigned int height;

public:
    box(int width, int length, int height);
    box(const box &b);
    static box init(int width, int length, int height);
    unsigned int get_width();
    unsigned int get_length();
    unsigned int get_height();
};

#endif

//box.cpp
#include "box.hpp"
#include <stdexcept>

box::box(const box &b)
{
    this->width = b.width;
    this->length = b.length;
    this->height = b.height;
}

box::box(int width, int length, int height)
{
    if (width <= 0)  throw std::invalid_argument("Высота коробки должна быть положительной");
    if (length <= 0) throw std::invalid_argument("Длина коробки должна быть положительной");
    if (height <= 0) throw std::invalid_argument("Высота коробки должна быть положительной");

    this->width = width;
    this->length = length;
    this->height = height;
}

box box::init(int width, int length, int height)
{
    return box(width, length, height);
}

unsigned int box::get_width()
{
    return this->width;
}

unsigned int box::get_length()
{
    return this->length;
}

unsigned int box::get_height()
{
    return this->height;
}

// main.cpp
#include "box.hpp"
#include <iostream>

void print_volume(box* b)
{
    std::cout << b->get_length() * b->get_width() * b->get_height() << std::endl;
}

int main(int argc, char const *argv[])
{
    box boxes[4] = {
        box::init(1, 1, 2),
        box::init(2, 3, 4),
        box::init(4, 5, 6),
        box::init(7, 8, 9)
    };

    for (int i = 3; i >= 0; i--) print_volume(&boxes[i]);

    return 0;
}