I just need to Item.cpp and item.h files please I'm having a bit of difficulty with it thanks. The POS.h and Error.h is there for reference to help understand the solution. This is the POS.h file!!! const double TAX = 0.13; const int MAX_SKU_LEN = 7; const int MAX_NAME_LEN = 40; const int MIN_YEAR = 2000; const int MAX_YEAR = 2030; const int MAX_STOCK_NUMBER = 99; const int MAX_NO_ITEMS = 2000; const int POS_LIST = 1; const int POS_FORM = 2; const char* ERROR_POS_SKU = "SKU too long"; const char* ERROR_POS_NAME = "Item name too long"; const char* ERROR_POS_PRICE = "Invalid price value"; const char* ERROR_POS_TAX = "Invalid tax status"; const char* ERROR_POS_QTY = "Invalid quantity value"; const char* ERROR_POS_STOCK = "Item out of stock"; const char* ERROR_POS_EMPTY = "Invalid Empty Item"; This is the Error class!!! class Error{ char* m_message; public: Error(); Error(constchar* errorMessage); Error& operator=(constchar* errorMessage); operatorbool() const; ~Error(); void clear(); bool isClear() const; constchar* message() const; std::ostream& write(std::ostream& os); }; std::ostream& operator<<(std::ostream&, Error& em); } # Milestone 3 Before starting milestone 3, add the following constant values to `POS.h` header file: ## Additional constant values ```text MAX_NAME_LEN: 40 POS_LIST: 1 POS_FORM: 2 ERROR_POS_SKU: "SKU too long" ERROR_POS_NAME: "Item name too long" ERROR_POS_PRICE: "Invalid price value" ERROR_POS_TAX: "Invalid tax status" ERROR_POS_QTY: "Invalid quantity value" ERROR_POS_STOCK: "Item out of stock" ERROR_POS_EMPTY: "Invalid Empty Item" `` For the third milestone of the project, you will create two classes: `PosIO` and `Item`. Milestone 3 is dependent on the `Error` class only. (You do not need the other classes created in milestones 1 and 2 at this stage) ## PosIO interface Create a class called `PosIO` as an interface for console and file input and output operations. This class will only define 4 pure virtual methods and a virtual empty destructor. ### Pure Virtual Methods #### write Receives and returns references of `ostream`. This method does not modify its owner. #### read Receives and returns references of `istream`. #### save Receives and returns references of `ofstream`. This method does not modify its owner. #### load Receives and returns references of `ifstream`. ### Insertion and Extraction operator overloads. #### operator<< Implement two insertion `operator<<` operator overloads that invoke the `write` and `save` pure virtual methods to work with `ostream` and `ofstream`. #### operator>> Implement two extraction `operator>>` operator overloads that invoke the `read` and `load` pure virtual methods to work with `istream` and `ifstream`. Item Abstract class Create a class called `Item` to encapsulate an Item to be sold by the POS system. ### Private Attributes The Item class has the following mandatory attributes: #### SKU A C-string to keep an SKU code up to `MAX_SKU_LEN` characters. #### Name A dynamically alloca.

1. I just need to Item.cpp and item.h files please I'm having a bit of difficulty with it thanks. The
POS.h and Error.h is there for reference to help understand the solution.
This is the POS.h file!!!
const double TAX = 0.13;
const int MAX_SKU_LEN = 7;
const int MAX_NAME_LEN = 40;
const int MIN_YEAR = 2000;
const int MAX_YEAR = 2030;
const int MAX_STOCK_NUMBER = 99;
const int MAX_NO_ITEMS = 2000;
const int POS_LIST = 1;
const int POS_FORM = 2;
const char* ERROR_POS_SKU = "SKU too long";
const char* ERROR_POS_NAME = "Item name too long";
const char* ERROR_POS_PRICE = "Invalid price value";
const char* ERROR_POS_TAX = "Invalid tax status";
const char* ERROR_POS_QTY = "Invalid quantity value";
const char* ERROR_POS_STOCK = "Item out of stock";
const char* ERROR_POS_EMPTY = "Invalid Empty Item";
This is the Error class!!!
class Error{
char* m_message;
public:
Error();
Error(constchar* errorMessage);
Error& operator=(constchar* errorMessage);
operatorbool() const;
~Error();
void clear();
bool isClear() const;
constchar* message() const;
std::ostream& write(std::ostream& os);
};
std::ostream& operator<<(std::ostream&, Error& em);

2. }
# Milestone 3
Before starting milestone 3, add the following constant values to `POS.h` header file:
## Additional constant values
```text
MAX_NAME_LEN: 40
POS_LIST: 1
POS_FORM: 2
ERROR_POS_SKU: "SKU too long"
ERROR_POS_NAME: "Item name too long"
ERROR_POS_PRICE: "Invalid price value"
ERROR_POS_TAX: "Invalid tax status"
ERROR_POS_QTY: "Invalid quantity value"
ERROR_POS_STOCK: "Item out of stock"
ERROR_POS_EMPTY: "Invalid Empty Item"
``
For the third milestone of the project, you will create two classes: `PosIO` and `Item`. Milestone
3 is dependent on the `Error` class only. (You do not need the other classes created in milestones
1 and 2 at this stage)
## PosIO interface
Create a class called `PosIO` as an interface for console and file input and output operations.
This class will only define 4 pure virtual methods and a virtual empty destructor.
### Pure Virtual Methods
#### write
Receives and returns references of `ostream`. This method does not modify its owner.
#### read
Receives and returns references of `istream`.
#### save
Receives and returns references of `ofstream`. This method does not modify its owner.
#### load

3. Receives and returns references of `ifstream`.
### Insertion and Extraction operator overloads.
#### operator<<
Implement two insertion `operator<<` operator overloads that invoke the `write` and `save` pure
virtual methods to work with `ostream` and `ofstream`.
#### operator>>
Implement two extraction `operator>>` operator overloads that invoke the `read` and `load` pure
virtual methods to work with `istream` and `ifstream`.
Item Abstract class
Create a class called `Item` to encapsulate an Item to be sold by the POS system.
### Private Attributes
The Item class has the following mandatory attributes:
#### SKU
A C-string to keep an SKU code up to `MAX_SKU_LEN` characters.
#### Name
A dynamically allocated C-string to keep the name of the `Item` up to `MAX_NAME_LEN`
characters.
#### Price
A double value
#### Taxed
A boolean that indicates if the Item is taxable or not.
#### Quantity
An integer value for the stock number of the `Item`. (number of items in the shop)
#### diaplayType
An integer flag that can be either `POS_LIST` to display the Item in List mode or `POS_FORM`
to display the Item in Form mode.
### Protect Attribute
#### Error State
An Error object to keep the error status of the Item.
### Constructor
Item is instantiated using no arguments. In this case, an Item is set to an invalid Empty state (we

4. will refer to this as `empty` from now on).
### Rule of three
An Item can be copied or assigned to another item safely and is destroyed with no memory leak.
### Member operator overloads
#### operator==
Compares two Items and returns true if the `SKU` codes are identical.
#### operator>
Compares two items alphabetically based on their names.
#### opertor+=
Adds an integer value (right-hand operand) to the quantity and returns the quantity. If the sum of
the value and the quantity exceeds the `MAX_STOCK_NUMBER` then the quantity will be set
to `MAX_STOCK_NUMBER` and the Item error will be set to `ERROR_POS_QTY`.
#### operator-=
Reduces the quantity by the right-hand value and returns the quantity. If the value is more than
the quantity then the quantity will be set to zero and the Item error will be set to
`ERROR_POS_STOCK`.
#### bool type conversion
Returns the opposite of the status of the error attribute. This method does not modify the object.
### helper += operator overload
Overload the `operator+=` to receive a double reference as the left-hand operand and a constant
reference of Item as the right-hand operator. This operator should add the product of
[cost()](#cost-query) by [quantity()](#quantity-query) of the Item to the double operand and then
return the value.
### Member function (Methods)
This pure virtual method returns a character as the type indicator of the item in future
descendants of the Item. This method does not modify the object.
#### displayType
Receives an integer (`POS_LIST` or `POS_FORM`) and sets the corresponding attribute. This
method returns the reference of the current object.

5. #### cost query
Returns the cost of the Item; that is the price of the item (plus tax if the item is taxable). This
method does not modify the object.
#### quantity query
Returns the quantity of the Item. This method does not modify the object.
#### clear
Clears the error status of the object and then returns the reference of the current object.
### IO
Implement the four pure virtual methods of the base class as follows:
#### write
1. If in POS_LIST mode, it will print the object as follows:
```text
1234 |Screw Driver | 12.32| X | 90| 1252.94|
4567 |Tape Measure - Level| 112.30| | 10| 1123.00|
```
- Name: if longer than 20 characters, only the first 20 will be printed
- Taxed: if true `X` is printed or else space
- After the line is printed, no newlines are printed.
2. If in POS_FORM mode, it will print as follows:
```text
=============v
Name: Screw Driver
Sku: 1234
Price: 12.32
Price + tax: 13.92
Stock Qty: 90
=============v
Name: Tape Measure - Level - Laser - Combo
Sku: 4567
Price: 112.30
Price + tax: N/A

6. Stock Qty: 10
```
- At the end, a newline is printed.
3. If the Item is erroneous only the error object is printed (with no newline after).
In the end, the ostream reference is returned.
#### save
Save the data in a comma-separated format as follows:
First, the [itemType](#itemtype-query) is printed and then all the attributes are saved separated
by commas. No newline is saved at the end.
In the following example, we assume the derived class's [itemType](#itemtype-query) function is
returning 'T'.
```text
T,1234,Screw Driver,12.32,1,89
T,4567,Tape Measure - Level - Laser - Combo,112.30,0,9
```
If the Item is erroneous the error object is inserted into `cerr` and not the ofstream (with a
newline after).
In the end, the ofstream reference is returned.
#### read
Performs fool-proof data entry.
The attributes are read in the following order:
SKU, Name, Price, Taxed or not and Quantity.
After each data entry, the value is validated, if invalid the [proper error message](#additional-
constant-values) is printed and in the next line at the prompt (`>`) the value is re-entered. This
repeats until a valid value is entered. See [Execution Sample](#execution-sample).
In the end, the reference of istream is returned.

7. ```text
Sku
> 12345
Name
> Hammer
Price
> 23.99
Taxed?
(Y)es/(N)o: y
Quantity
> 35
```
#### load
First, the error status will be [clear](#clear-1)ed
Then reads all the values from the ifstream object in a comma-separated format (assuming the
data begins with the SKU) in local variables (not directly into the attributes of the item).
If after the reading the ifstream is not in a failure state, it will validate the values one by one and
if any of the validation fails, the error message is set to the proper message and validation stops.
At the end of the validation process, if there is no error, the attributes are set to the validated
values.
The reference of the ifstream object is returned at the end.
#### billPrint
This function will receive and return the ostream object.
The bill print function will only print the Name, taxed price, and if the item is taxed or not:
```text
| Screw Driver | 13.92 | T |
| Tape Measure - Level| 112.30 | |
```

8. - Name: only the first 20 characters are printed
- Taxed: if the item is taxed, `T` and otherwise, a space is printed.