template

class DList $\{$

friend class UnitTests$\_$Lab$3$; $//$ Giving access to test code

struct Node $\{$

$//$ NOTE: Values set to $-1$ for unit test purposes

Type data;

Node$*$ next $=$ reinterpret$\_$cast$(-1)$;

Node$*$ prev $=$ reinterpret$\_$cast$(-1)$;

Node$($const Type& $\_$data, Node$*\_$next $=$ nullptr, Node$*\_$prev $=$ nullptr$)\{$

$//$ TODO: Implement this method

$\}$

$\}$;

public:

class Iterator $\{$

public:

Node$*$ mCurr $=$ reinterpret$\_$cast$(-1)$;

Iterator& operator$++()\{$

$//$ TODO: Implement this method

$\}$

Iterator operator$++($int$)\{$

$//$ TODO: Implement this method

$\}$

Iterator& operator$--()\{$

$//$ TODO: Implement this method

$\}$

Iterator operator$--($int$)\{$

$//$ TODO: Implement this method

$\}$

Type& operator$*()\{$

$//$ TODO: Implement this method

$\}$

bool operator $!=($const Iterator& $\_$iter$)$ const $\{$

return mCurr $!=\_$iter.mCurr;

$\}$

$\}$;

$//$ Data members

$//$ NOTE: All values set to $-1$ for unit test purposes

Node$*$ mHead $=$ reinterpret$\_$cast$(-1)$;

Node$*$ mTail $=$ reinterpret$\_$cast$(-1)$;

size$\_$t mSize $=-1$;

public:

DList$()\{$

$//$ TODO: Implement this method

$\}$

~DList$()\{$

$//$ TODO: Implement this method

$\}$

DList$($const DList& $\_$copy$)\{$

$//$ TODO: Implement this method

$\}$

DList& operator$=($const DList& $\_$assign$)\{$

$//$ TODO: Implement this method

$\}$

void AddHead$($const Type& $\_$data$)\{$

$//$ TODO: Implement this method

$\}$

void AddTail$($const Type& $\_$data$)\{$

$//$ TODO: Implement this method

$\}$

void Clear$()\{$

$//$ TODO: Implement this method

$\}$

Iterator Insert$($Iterator& $\_$iter, const Type& $\_$data$)\{$

$//$ Implement this method

$\}$

Iterator Erase$($Iterator& $\_$iter$)\{$

$//$ TODO: Implement this method

$\}$

Iterator Begin$()$ const $\{$

$//$ TODO: Implement this method

$\}$

Iterator End$()$ const $\{$

$//$ TODO: Implement this method

$\}$

$\}$;