I need to make the list.hpp file in c$++$ based on the list.h file, I would appreciate it if you could explain each part in detail step by step and show me the final version that was integrated at the end.

A header file List.h is provided, which contains the interfaces of the doubly$-$linked list class template List. In particular, it contains a nested Node structure, and two nested iterators class $($iterator and const$\_$iterator$).$ You cannot change anything in the List.h file.

List.h

#ifndef DL$\_$LIST$\_$H

#define DL$\_$LIST$\_$H

#include

#include

namespace cop$4530\{$

template

class List $\{$

private:

$//$ nested Node class

struct Node $\{$

T data;

Node $*$prev;

Node $*$next;

Node$($const T & d $=$ T$\{\},$ Node $*$p $=$ nullptr, Node $*$n $=$ nullptr$)$

: data$\{$d$\},$ prev$\{$p$\},$ next$\{$n$\}\{\}$

Node$($T && d$,$ Node $*$p $=$ nullptr, Node $*$n $=$ nullptr$)$

: data$\{$std::move$($d$)\},$ prev$\{$p$\},$ next$\{$n$\}\{\}$

$\}$;

public:

$//$nested const$\_$iterator class

class const$\_$iterator $\{$

public:

const$\_$iterator$()$;

const T & operator$*()$ const;

const$\_$iterator & operator$++()$;

const$\_$iterator operator$++($int$)$;

const$\_$iterator & operator$--()$;

const$\_$iterator operator$--($int$)$;

bool operator$==($const const$\_$iterator &rhs$)$ const;

bool operator!$=($const const$\_$iterator &rhs$)$ const;

protected:

Node $*$current;

T & retrieve$()$ const;

const$\_$iterator$($Node $*$p$)$;

friend class List;

$\}$;

class iterator : public const$\_$iterator $\{$

public:

iterator$()$;

T & operator$*()$;

const T & operator$*()$ const;

iterator & operator$++()$;

iterator operator$++($int$)$;

iterator & operator$--()$;

iterator operator$--($int$)$;

protected:

iterator$($Node $*$p$)$;

friend class List;

$\}$;

public:

List$()$;

List$($const List &rhs$)$;

List$($List && rhs$)$;

explicit List$($int num, const T& val $=$ T$\{\})$;

List$($const$\_$iterator start, const$\_$iterator end$)$;

List $($std::initializer$\_$list iList$)$;

~List$()$; $//$ destructor

const List& operator$=($const List &rhs$)$;

List & operator$=($List && rhs$)$;

List& operator$=($std::initializer$\_$list iList$)$;

int size$()$ const;

bool empty$()$ const;

void clear$()$;

void reverse$()$;

T& front$()$;

const T& front$()$ const;

T& back$()$;

const T& back$()$ const;

void push$\_$front$($const T & val$)$;

void push$\_$front$($T && val$)$;

void push$\_$back$($const T & val$)$;

void push$\_$back$($T && val$)$;

void pop$\_$front$()$;

void pop$\_$back$()$;

void remove$($const T &val$)$;

template

void remove$\_$if$($PREDICATE pred$)$;

void print$($std::ostream& os$,$ char ofc $=\text{'}\text{'})$ const;

iterator begin$()$;

const$\_$iterator begin$()$ const;

iterator end$()$;

const$\_$iterator end$()$ const;

iterator insert$($iterator itr, const T& val$)$;

iterator insert$($iterator itr, T && val$)$;

iterator erase$($iterator itr$)$;

iterator erase$($iterator start, iterator end$)$;

private:

int theSize;

Node $*$head;

Node $*$tail;

void init$()$;

$\}$;

template

bool operator$==($const List & lhs$,$ const List &rhs$)$;

template

bool operator!$=($const List & lhs$,$ const List &rhs$)$;

template

std::ostream & operatorstd::ostream &os$,$ const List &l$)$;

#include "List.hpp$"$

$\}//$ end of namespace $4530$

#endif